diff --git a/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.create_backup.js b/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.create_backup.js
index 522528ea9a2..a1f61a75bd8 100644
--- a/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.create_backup.js
+++ b/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.create_backup.js
@@ -23,6 +23,9 @@
 function main(parent, backup, backupId) {
   // [START file_v1_generated_CloudFilestoreManager_CreateBackup_async]
   /**
+   * This snippet has been automatically generated and should be regarded as a code template only.
+   * It will require modifications to work.
+   * It may require correct/in-range values for request initialization.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.create_instance.js b/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.create_instance.js
index f1ee31af676..2e7737982f8 100644
--- a/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.create_instance.js
+++ b/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.create_instance.js
@@ -23,6 +23,9 @@
 function main(parent, instanceId, instance) {
   // [START file_v1_generated_CloudFilestoreManager_CreateInstance_async]
   /**
+   * This snippet has been automatically generated and should be regarded as a code template only.
+   * It will require modifications to work.
+   * It may require correct/in-range values for request initialization.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.delete_backup.js b/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.delete_backup.js
index e7a3f857a5d..0ab3b8c2b9b 100644
--- a/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.delete_backup.js
+++ b/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.delete_backup.js
@@ -23,6 +23,9 @@
 function main(name) {
   // [START file_v1_generated_CloudFilestoreManager_DeleteBackup_async]
   /**
+   * This snippet has been automatically generated and should be regarded as a code template only.
+   * It will require modifications to work.
+   * It may require correct/in-range values for request initialization.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.delete_instance.js b/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.delete_instance.js
index 160d13046bd..deb4a52129b 100644
--- a/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.delete_instance.js
+++ b/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.delete_instance.js
@@ -23,6 +23,9 @@
 function main(name) {
   // [START file_v1_generated_CloudFilestoreManager_DeleteInstance_async]
   /**
+   * This snippet has been automatically generated and should be regarded as a code template only.
+   * It will require modifications to work.
+   * It may require correct/in-range values for request initialization.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.get_backup.js b/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.get_backup.js
index dbf655241ca..8cbde7304d7 100644
--- a/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.get_backup.js
+++ b/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.get_backup.js
@@ -23,6 +23,9 @@
 function main(name) {
   // [START file_v1_generated_CloudFilestoreManager_GetBackup_async]
   /**
+   * This snippet has been automatically generated and should be regarded as a code template only.
+   * It will require modifications to work.
+   * It may require correct/in-range values for request initialization.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.get_instance.js b/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.get_instance.js
index 64c7a269f81..a494686408e 100644
--- a/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.get_instance.js
+++ b/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.get_instance.js
@@ -23,6 +23,9 @@
 function main(name) {
   // [START file_v1_generated_CloudFilestoreManager_GetInstance_async]
   /**
+   * This snippet has been automatically generated and should be regarded as a code template only.
+   * It will require modifications to work.
+   * It may require correct/in-range values for request initialization.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.list_backups.js b/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.list_backups.js
index 37fe21306b2..fa20cb0b802 100644
--- a/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.list_backups.js
+++ b/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.list_backups.js
@@ -23,6 +23,9 @@
 function main(parent) {
   // [START file_v1_generated_CloudFilestoreManager_ListBackups_async]
   /**
+   * This snippet has been automatically generated and should be regarded as a code template only.
+   * It will require modifications to work.
+   * It may require correct/in-range values for request initialization.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.list_instances.js b/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.list_instances.js
index 800afa0218c..67d55401c2e 100644
--- a/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.list_instances.js
+++ b/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.list_instances.js
@@ -23,6 +23,9 @@
 function main(parent) {
   // [START file_v1_generated_CloudFilestoreManager_ListInstances_async]
   /**
+   * This snippet has been automatically generated and should be regarded as a code template only.
+   * It will require modifications to work.
+   * It may require correct/in-range values for request initialization.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.restore_instance.js b/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.restore_instance.js
index 2be0689e19d..2c691937fc6 100644
--- a/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.restore_instance.js
+++ b/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.restore_instance.js
@@ -23,6 +23,9 @@
 function main(name, fileShare) {
   // [START file_v1_generated_CloudFilestoreManager_RestoreInstance_async]
   /**
+   * This snippet has been automatically generated and should be regarded as a code template only.
+   * It will require modifications to work.
+   * It may require correct/in-range values for request initialization.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.update_backup.js b/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.update_backup.js
index 153cf08ed8b..8457ab63a4c 100644
--- a/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.update_backup.js
+++ b/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.update_backup.js
@@ -23,6 +23,9 @@
 function main(backup, updateMask) {
   // [START file_v1_generated_CloudFilestoreManager_UpdateBackup_async]
   /**
+   * This snippet has been automatically generated and should be regarded as a code template only.
+   * It will require modifications to work.
+   * It may require correct/in-range values for request initialization.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.update_instance.js b/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.update_instance.js
index 80af3634128..a58df33a8d9 100644
--- a/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.update_instance.js
+++ b/packages/google-cloud-filestore/samples/generated/v1/cloud_filestore_manager.update_instance.js
@@ -23,6 +23,9 @@
 function main() {
   // [START file_v1_generated_CloudFilestoreManager_UpdateInstance_async]
   /**
+   * This snippet has been automatically generated and should be regarded as a code template only.
+   * It will require modifications to work.
+   * It may require correct/in-range values for request initialization.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/packages/google-cloud-filestore/samples/generated/v1/snippet_metadata.google.cloud.filestore.v1.json b/packages/google-cloud-filestore/samples/generated/v1/snippet_metadata.google.cloud.filestore.v1.json
index cab0260d63d..9959a93643a 100644
--- a/packages/google-cloud-filestore/samples/generated/v1/snippet_metadata.google.cloud.filestore.v1.json
+++ b/packages/google-cloud-filestore/samples/generated/v1/snippet_metadata.google.cloud.filestore.v1.json
@@ -22,7 +22,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 73,
+                    "end": 76,
                     "type": "FULL"
                 }
             ],
@@ -78,7 +78,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 51,
+                    "end": 54,
                     "type": "FULL"
                 }
             ],
@@ -118,7 +118,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 64,
+                    "end": 67,
                     "type": "FULL"
                 }
             ],
@@ -166,7 +166,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 59,
+                    "end": 62,
                     "type": "FULL"
                 }
             ],
@@ -210,7 +210,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 63,
+                    "end": 66,
                     "type": "FULL"
                 }
             ],
@@ -258,7 +258,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 52,
+                    "end": 55,
                     "type": "FULL"
                 }
             ],
@@ -298,7 +298,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 74,
+                    "end": 77,
                     "type": "FULL"
                 }
             ],
@@ -354,7 +354,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 51,
+                    "end": 54,
                     "type": "FULL"
                 }
             ],
@@ -394,7 +394,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 68,
+                    "end": 71,
                     "type": "FULL"
                 }
             ],
@@ -442,7 +442,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 52,
+                    "end": 55,
                     "type": "FULL"
                 }
             ],
@@ -482,7 +482,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 57,
+                    "end": 60,
                     "type": "FULL"
                 }
             ],
diff --git a/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.create_backup.js b/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.create_backup.js
index 8a1d810399f..aa4b06a679b 100644
--- a/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.create_backup.js
+++ b/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.create_backup.js
@@ -23,6 +23,9 @@
 function main(parent, backup, backupId) {
   // [START file_v1beta1_generated_CloudFilestoreManager_CreateBackup_async]
   /**
+   * This snippet has been automatically generated and should be regarded as a code template only.
+   * It will require modifications to work.
+   * It may require correct/in-range values for request initialization.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.create_instance.js b/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.create_instance.js
index efd8d806f5b..62c0b12052c 100644
--- a/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.create_instance.js
+++ b/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.create_instance.js
@@ -23,6 +23,9 @@
 function main(parent, instanceId, instance) {
   // [START file_v1beta1_generated_CloudFilestoreManager_CreateInstance_async]
   /**
+   * This snippet has been automatically generated and should be regarded as a code template only.
+   * It will require modifications to work.
+   * It may require correct/in-range values for request initialization.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.delete_backup.js b/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.delete_backup.js
index 29babc4b0d9..c02be6c5b5d 100644
--- a/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.delete_backup.js
+++ b/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.delete_backup.js
@@ -23,6 +23,9 @@
 function main(name) {
   // [START file_v1beta1_generated_CloudFilestoreManager_DeleteBackup_async]
   /**
+   * This snippet has been automatically generated and should be regarded as a code template only.
+   * It will require modifications to work.
+   * It may require correct/in-range values for request initialization.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.delete_instance.js b/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.delete_instance.js
index 115388bfcbf..e6ce14ab7d1 100644
--- a/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.delete_instance.js
+++ b/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.delete_instance.js
@@ -23,6 +23,9 @@
 function main(name) {
   // [START file_v1beta1_generated_CloudFilestoreManager_DeleteInstance_async]
   /**
+   * This snippet has been automatically generated and should be regarded as a code template only.
+   * It will require modifications to work.
+   * It may require correct/in-range values for request initialization.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.get_backup.js b/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.get_backup.js
index 6a1ba8dcb04..c785a3781d7 100644
--- a/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.get_backup.js
+++ b/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.get_backup.js
@@ -23,6 +23,9 @@
 function main(name) {
   // [START file_v1beta1_generated_CloudFilestoreManager_GetBackup_async]
   /**
+   * This snippet has been automatically generated and should be regarded as a code template only.
+   * It will require modifications to work.
+   * It may require correct/in-range values for request initialization.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.get_instance.js b/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.get_instance.js
index 5b1b616b021..cfd5079fb75 100644
--- a/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.get_instance.js
+++ b/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.get_instance.js
@@ -23,6 +23,9 @@
 function main(name) {
   // [START file_v1beta1_generated_CloudFilestoreManager_GetInstance_async]
   /**
+   * This snippet has been automatically generated and should be regarded as a code template only.
+   * It will require modifications to work.
+   * It may require correct/in-range values for request initialization.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.list_backups.js b/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.list_backups.js
index 20b4215eab0..7869cd6805f 100644
--- a/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.list_backups.js
+++ b/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.list_backups.js
@@ -23,6 +23,9 @@
 function main(parent) {
   // [START file_v1beta1_generated_CloudFilestoreManager_ListBackups_async]
   /**
+   * This snippet has been automatically generated and should be regarded as a code template only.
+   * It will require modifications to work.
+   * It may require correct/in-range values for request initialization.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.list_instances.js b/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.list_instances.js
index 550c331c3ce..80063ca8554 100644
--- a/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.list_instances.js
+++ b/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.list_instances.js
@@ -23,6 +23,9 @@
 function main(parent) {
   // [START file_v1beta1_generated_CloudFilestoreManager_ListInstances_async]
   /**
+   * This snippet has been automatically generated and should be regarded as a code template only.
+   * It will require modifications to work.
+   * It may require correct/in-range values for request initialization.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.restore_instance.js b/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.restore_instance.js
index feac01861bb..033044f5c2b 100644
--- a/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.restore_instance.js
+++ b/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.restore_instance.js
@@ -23,6 +23,9 @@
 function main(name, fileShare) {
   // [START file_v1beta1_generated_CloudFilestoreManager_RestoreInstance_async]
   /**
+   * This snippet has been automatically generated and should be regarded as a code template only.
+   * It will require modifications to work.
+   * It may require correct/in-range values for request initialization.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.update_backup.js b/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.update_backup.js
index d1c471ad7fc..119c22dd2f4 100644
--- a/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.update_backup.js
+++ b/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.update_backup.js
@@ -23,6 +23,9 @@
 function main(backup, updateMask) {
   // [START file_v1beta1_generated_CloudFilestoreManager_UpdateBackup_async]
   /**
+   * This snippet has been automatically generated and should be regarded as a code template only.
+   * It will require modifications to work.
+   * It may require correct/in-range values for request initialization.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.update_instance.js b/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.update_instance.js
index 176ad3d1cd0..d100b618398 100644
--- a/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.update_instance.js
+++ b/packages/google-cloud-filestore/samples/generated/v1beta1/cloud_filestore_manager.update_instance.js
@@ -23,6 +23,9 @@
 function main(updateMask, instance) {
   // [START file_v1beta1_generated_CloudFilestoreManager_UpdateInstance_async]
   /**
+   * This snippet has been automatically generated and should be regarded as a code template only.
+   * It will require modifications to work.
+   * It may require correct/in-range values for request initialization.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/packages/google-cloud-filestore/samples/generated/v1beta1/snippet_metadata.google.cloud.filestore.v1beta1.json b/packages/google-cloud-filestore/samples/generated/v1beta1/snippet_metadata.google.cloud.filestore.v1beta1.json
index 263d8d394c1..5d7947cde17 100644
--- a/packages/google-cloud-filestore/samples/generated/v1beta1/snippet_metadata.google.cloud.filestore.v1beta1.json
+++ b/packages/google-cloud-filestore/samples/generated/v1beta1/snippet_metadata.google.cloud.filestore.v1beta1.json
@@ -22,7 +22,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 73,
+                    "end": 76,
                     "type": "FULL"
                 }
             ],
@@ -78,7 +78,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 51,
+                    "end": 54,
                     "type": "FULL"
                 }
             ],
@@ -118,7 +118,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 66,
+                    "end": 69,
                     "type": "FULL"
                 }
             ],
@@ -166,7 +166,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 61,
+                    "end": 64,
                     "type": "FULL"
                 }
             ],
@@ -210,7 +210,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 68,
+                    "end": 71,
                     "type": "FULL"
                 }
             ],
@@ -262,7 +262,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 52,
+                    "end": 55,
                     "type": "FULL"
                 }
             ],
@@ -302,7 +302,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 74,
+                    "end": 77,
                     "type": "FULL"
                 }
             ],
@@ -358,7 +358,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 51,
+                    "end": 54,
                     "type": "FULL"
                 }
             ],
@@ -398,7 +398,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 66,
+                    "end": 69,
                     "type": "FULL"
                 }
             ],
@@ -446,7 +446,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 52,
+                    "end": 55,
                     "type": "FULL"
                 }
             ],
@@ -486,7 +486,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 57,
+                    "end": 60,
                     "type": "FULL"
                 }
             ],
diff --git a/packages/google-cloud-filestore/src/v1/cloud_filestore_manager_client.ts b/packages/google-cloud-filestore/src/v1/cloud_filestore_manager_client.ts
index 47d7bf1b6d5..a225be52adb 100644
--- a/packages/google-cloud-filestore/src/v1/cloud_filestore_manager_client.ts
+++ b/packages/google-cloud-filestore/src/v1/cloud_filestore_manager_client.ts
@@ -30,7 +30,6 @@ import {
 } from 'google-gax';
 
 import {Transform} from 'stream';
-import {RequestType} from 'google-gax/build/src/apitypes';
 import * as protos from '../../protos/protos';
 import jsonProtos = require('../../protos/protos.json');
 /**
@@ -418,7 +417,8 @@ export class CloudFilestoreManagerClient {
       const apiCall = this._gaxModule.createApiCall(
         callPromise,
         this._defaults[methodName],
-        descriptor
+        descriptor,
+        this._opts.fallback
       );
 
       this.innerApiCalls[methodName] = apiCall;
@@ -791,7 +791,7 @@ export class CloudFilestoreManagerClient {
     const decodeOperation = new gax.Operation(
       operation,
       this.descriptors.longrunning.createInstance,
-      gax.createDefaultBackoffSettings()
+      this._gaxModule.createDefaultBackoffSettings()
     );
     return decodeOperation as LROperation<
       protos.google.cloud.filestore.v1.Instance,
@@ -936,7 +936,7 @@ export class CloudFilestoreManagerClient {
     const decodeOperation = new gax.Operation(
       operation,
       this.descriptors.longrunning.updateInstance,
-      gax.createDefaultBackoffSettings()
+      this._gaxModule.createDefaultBackoffSettings()
     );
     return decodeOperation as LROperation<
       protos.google.cloud.filestore.v1.Instance,
@@ -1084,7 +1084,7 @@ export class CloudFilestoreManagerClient {
     const decodeOperation = new gax.Operation(
       operation,
       this.descriptors.longrunning.restoreInstance,
-      gax.createDefaultBackoffSettings()
+      this._gaxModule.createDefaultBackoffSettings()
     );
     return decodeOperation as LROperation<
       protos.google.cloud.filestore.v1.Instance,
@@ -1222,7 +1222,7 @@ export class CloudFilestoreManagerClient {
     const decodeOperation = new gax.Operation(
       operation,
       this.descriptors.longrunning.deleteInstance,
-      gax.createDefaultBackoffSettings()
+      this._gaxModule.createDefaultBackoffSettings()
     );
     return decodeOperation as LROperation<
       protos.google.protobuf.Empty,
@@ -1371,7 +1371,7 @@ export class CloudFilestoreManagerClient {
     const decodeOperation = new gax.Operation(
       operation,
       this.descriptors.longrunning.createBackup,
-      gax.createDefaultBackoffSettings()
+      this._gaxModule.createDefaultBackoffSettings()
     );
     return decodeOperation as LROperation<
       protos.google.cloud.filestore.v1.Backup,
@@ -1509,7 +1509,7 @@ export class CloudFilestoreManagerClient {
     const decodeOperation = new gax.Operation(
       operation,
       this.descriptors.longrunning.deleteBackup,
-      gax.createDefaultBackoffSettings()
+      this._gaxModule.createDefaultBackoffSettings()
     );
     return decodeOperation as LROperation<
       protos.google.protobuf.Empty,
@@ -1649,7 +1649,7 @@ export class CloudFilestoreManagerClient {
     const decodeOperation = new gax.Operation(
       operation,
       this.descriptors.longrunning.updateBackup,
-      gax.createDefaultBackoffSettings()
+      this._gaxModule.createDefaultBackoffSettings()
     );
     return decodeOperation as LROperation<
       protos.google.cloud.filestore.v1.Backup,
@@ -1812,7 +1812,7 @@ export class CloudFilestoreManagerClient {
     const callSettings = defaultCallSettings.merge(options);
     this.initialize();
     return this.descriptors.page.listInstances.createStream(
-      this.innerApiCalls.listInstances as gax.GaxCall,
+      this.innerApiCalls.listInstances as GaxCall,
       request,
       callSettings
     );
@@ -1869,7 +1869,7 @@ export class CloudFilestoreManagerClient {
     this.initialize();
     return this.descriptors.page.listInstances.asyncIterate(
       this.innerApiCalls['listInstances'] as GaxCall,
-      request as unknown as RequestType,
+      request as {},
       callSettings
     ) as AsyncIterable<protos.google.cloud.filestore.v1.IInstance>;
   }
@@ -2025,7 +2025,7 @@ export class CloudFilestoreManagerClient {
     const callSettings = defaultCallSettings.merge(options);
     this.initialize();
     return this.descriptors.page.listBackups.createStream(
-      this.innerApiCalls.listBackups as gax.GaxCall,
+      this.innerApiCalls.listBackups as GaxCall,
       request,
       callSettings
     );
@@ -2083,7 +2083,7 @@ export class CloudFilestoreManagerClient {
     this.initialize();
     return this.descriptors.page.listBackups.asyncIterate(
       this.innerApiCalls['listBackups'] as GaxCall,
-      request as unknown as RequestType,
+      request as {},
       callSettings
     ) as AsyncIterable<protos.google.cloud.filestore.v1.IBackup>;
   }
diff --git a/packages/google-cloud-filestore/src/v1beta1/cloud_filestore_manager_client.ts b/packages/google-cloud-filestore/src/v1beta1/cloud_filestore_manager_client.ts
index 8f7850717a6..a76fcc0df21 100644
--- a/packages/google-cloud-filestore/src/v1beta1/cloud_filestore_manager_client.ts
+++ b/packages/google-cloud-filestore/src/v1beta1/cloud_filestore_manager_client.ts
@@ -30,7 +30,6 @@ import {
 } from 'google-gax';
 
 import {Transform} from 'stream';
-import {RequestType} from 'google-gax/build/src/apitypes';
 import * as protos from '../../protos/protos';
 import jsonProtos = require('../../protos/protos.json');
 /**
@@ -425,7 +424,8 @@ export class CloudFilestoreManagerClient {
       const apiCall = this._gaxModule.createApiCall(
         callPromise,
         this._defaults[methodName],
-        descriptor
+        descriptor,
+        this._opts.fallback
       );
 
       this.innerApiCalls[methodName] = apiCall;
@@ -815,7 +815,7 @@ export class CloudFilestoreManagerClient {
     const decodeOperation = new gax.Operation(
       operation,
       this.descriptors.longrunning.createInstance,
-      gax.createDefaultBackoffSettings()
+      this._gaxModule.createDefaultBackoffSettings()
     );
     return decodeOperation as LROperation<
       protos.google.cloud.filestore.v1beta1.Instance,
@@ -960,7 +960,7 @@ export class CloudFilestoreManagerClient {
     const decodeOperation = new gax.Operation(
       operation,
       this.descriptors.longrunning.updateInstance,
-      gax.createDefaultBackoffSettings()
+      this._gaxModule.createDefaultBackoffSettings()
     );
     return decodeOperation as LROperation<
       protos.google.cloud.filestore.v1beta1.Instance,
@@ -1111,7 +1111,7 @@ export class CloudFilestoreManagerClient {
     const decodeOperation = new gax.Operation(
       operation,
       this.descriptors.longrunning.restoreInstance,
-      gax.createDefaultBackoffSettings()
+      this._gaxModule.createDefaultBackoffSettings()
     );
     return decodeOperation as LROperation<
       protos.google.cloud.filestore.v1beta1.Instance,
@@ -1249,7 +1249,7 @@ export class CloudFilestoreManagerClient {
     const decodeOperation = new gax.Operation(
       operation,
       this.descriptors.longrunning.deleteInstance,
-      gax.createDefaultBackoffSettings()
+      this._gaxModule.createDefaultBackoffSettings()
     );
     return decodeOperation as LROperation<
       protos.google.protobuf.Empty,
@@ -1396,7 +1396,7 @@ export class CloudFilestoreManagerClient {
     const decodeOperation = new gax.Operation(
       operation,
       this.descriptors.longrunning.createBackup,
-      gax.createDefaultBackoffSettings()
+      this._gaxModule.createDefaultBackoffSettings()
     );
     return decodeOperation as LROperation<
       protos.google.cloud.filestore.v1beta1.Backup,
@@ -1534,7 +1534,7 @@ export class CloudFilestoreManagerClient {
     const decodeOperation = new gax.Operation(
       operation,
       this.descriptors.longrunning.deleteBackup,
-      gax.createDefaultBackoffSettings()
+      this._gaxModule.createDefaultBackoffSettings()
     );
     return decodeOperation as LROperation<
       protos.google.protobuf.Empty,
@@ -1674,7 +1674,7 @@ export class CloudFilestoreManagerClient {
     const decodeOperation = new gax.Operation(
       operation,
       this.descriptors.longrunning.updateBackup,
-      gax.createDefaultBackoffSettings()
+      this._gaxModule.createDefaultBackoffSettings()
     );
     return decodeOperation as LROperation<
       protos.google.cloud.filestore.v1beta1.Backup,
@@ -1837,7 +1837,7 @@ export class CloudFilestoreManagerClient {
     const callSettings = defaultCallSettings.merge(options);
     this.initialize();
     return this.descriptors.page.listInstances.createStream(
-      this.innerApiCalls.listInstances as gax.GaxCall,
+      this.innerApiCalls.listInstances as GaxCall,
       request,
       callSettings
     );
@@ -1894,7 +1894,7 @@ export class CloudFilestoreManagerClient {
     this.initialize();
     return this.descriptors.page.listInstances.asyncIterate(
       this.innerApiCalls['listInstances'] as GaxCall,
-      request as unknown as RequestType,
+      request as {},
       callSettings
     ) as AsyncIterable<protos.google.cloud.filestore.v1beta1.IInstance>;
   }
@@ -2056,7 +2056,7 @@ export class CloudFilestoreManagerClient {
     const callSettings = defaultCallSettings.merge(options);
     this.initialize();
     return this.descriptors.page.listBackups.createStream(
-      this.innerApiCalls.listBackups as gax.GaxCall,
+      this.innerApiCalls.listBackups as GaxCall,
       request,
       callSettings
     );
@@ -2114,7 +2114,7 @@ export class CloudFilestoreManagerClient {
     this.initialize();
     return this.descriptors.page.listBackups.asyncIterate(
       this.innerApiCalls['listBackups'] as GaxCall,
-      request as unknown as RequestType,
+      request as {},
       callSettings
     ) as AsyncIterable<protos.google.cloud.filestore.v1beta1.IBackup>;
   }
diff --git a/packages/google-cloud-filestore/test/gapic_cloud_filestore_manager_v1.ts b/packages/google-cloud-filestore/test/gapic_cloud_filestore_manager_v1.ts
index 914d07c4894..825d6e3b8f7 100644
--- a/packages/google-cloud-filestore/test/gapic_cloud_filestore_manager_v1.ts
+++ b/packages/google-cloud-filestore/test/gapic_cloud_filestore_manager_v1.ts
@@ -145,109 +145,111 @@ function stubAsyncIterationCall<ResponseType>(
 }
 
 describe('v1.CloudFilestoreManagerClient', () => {
-  it('has servicePath', () => {
-    const servicePath =
-      cloudfilestoremanagerModule.v1.CloudFilestoreManagerClient.servicePath;
-    assert(servicePath);
-  });
+  describe('Common methods', () => {
+    it('has servicePath', () => {
+      const servicePath =
+        cloudfilestoremanagerModule.v1.CloudFilestoreManagerClient.servicePath;
+      assert(servicePath);
+    });
 
-  it('has apiEndpoint', () => {
-    const apiEndpoint =
-      cloudfilestoremanagerModule.v1.CloudFilestoreManagerClient.apiEndpoint;
-    assert(apiEndpoint);
-  });
+    it('has apiEndpoint', () => {
+      const apiEndpoint =
+        cloudfilestoremanagerModule.v1.CloudFilestoreManagerClient.apiEndpoint;
+      assert(apiEndpoint);
+    });
 
-  it('has port', () => {
-    const port =
-      cloudfilestoremanagerModule.v1.CloudFilestoreManagerClient.port;
-    assert(port);
-    assert(typeof port === 'number');
-  });
+    it('has port', () => {
+      const port =
+        cloudfilestoremanagerModule.v1.CloudFilestoreManagerClient.port;
+      assert(port);
+      assert(typeof port === 'number');
+    });
 
-  it('should create a client with no option', () => {
-    const client =
-      new cloudfilestoremanagerModule.v1.CloudFilestoreManagerClient();
-    assert(client);
-  });
+    it('should create a client with no option', () => {
+      const client =
+        new cloudfilestoremanagerModule.v1.CloudFilestoreManagerClient();
+      assert(client);
+    });
 
-  it('should create a client with gRPC fallback', () => {
-    const client =
-      new cloudfilestoremanagerModule.v1.CloudFilestoreManagerClient({
-        fallback: true,
-      });
-    assert(client);
-  });
+    it('should create a client with gRPC fallback', () => {
+      const client =
+        new cloudfilestoremanagerModule.v1.CloudFilestoreManagerClient({
+          fallback: true,
+        });
+      assert(client);
+    });
 
-  it('has initialize method and supports deferred initialization', async () => {
-    const client =
-      new cloudfilestoremanagerModule.v1.CloudFilestoreManagerClient({
-        credentials: {client_email: 'bogus', private_key: 'bogus'},
-        projectId: 'bogus',
-      });
-    assert.strictEqual(client.cloudFilestoreManagerStub, undefined);
-    await client.initialize();
-    assert(client.cloudFilestoreManagerStub);
-  });
+    it('has initialize method and supports deferred initialization', async () => {
+      const client =
+        new cloudfilestoremanagerModule.v1.CloudFilestoreManagerClient({
+          credentials: {client_email: 'bogus', private_key: 'bogus'},
+          projectId: 'bogus',
+        });
+      assert.strictEqual(client.cloudFilestoreManagerStub, undefined);
+      await client.initialize();
+      assert(client.cloudFilestoreManagerStub);
+    });
 
-  it('has close method for the initialized client', done => {
-    const client =
-      new cloudfilestoremanagerModule.v1.CloudFilestoreManagerClient({
-        credentials: {client_email: 'bogus', private_key: 'bogus'},
-        projectId: 'bogus',
+    it('has close method for the initialized client', done => {
+      const client =
+        new cloudfilestoremanagerModule.v1.CloudFilestoreManagerClient({
+          credentials: {client_email: 'bogus', private_key: 'bogus'},
+          projectId: 'bogus',
+        });
+      client.initialize();
+      assert(client.cloudFilestoreManagerStub);
+      client.close().then(() => {
+        done();
       });
-    client.initialize();
-    assert(client.cloudFilestoreManagerStub);
-    client.close().then(() => {
-      done();
     });
-  });
 
-  it('has close method for the non-initialized client', done => {
-    const client =
-      new cloudfilestoremanagerModule.v1.CloudFilestoreManagerClient({
-        credentials: {client_email: 'bogus', private_key: 'bogus'},
-        projectId: 'bogus',
+    it('has close method for the non-initialized client', done => {
+      const client =
+        new cloudfilestoremanagerModule.v1.CloudFilestoreManagerClient({
+          credentials: {client_email: 'bogus', private_key: 'bogus'},
+          projectId: 'bogus',
+        });
+      assert.strictEqual(client.cloudFilestoreManagerStub, undefined);
+      client.close().then(() => {
+        done();
       });
-    assert.strictEqual(client.cloudFilestoreManagerStub, undefined);
-    client.close().then(() => {
-      done();
     });
-  });
 
-  it('has getProjectId method', async () => {
-    const fakeProjectId = 'fake-project-id';
-    const client =
-      new cloudfilestoremanagerModule.v1.CloudFilestoreManagerClient({
-        credentials: {client_email: 'bogus', private_key: 'bogus'},
-        projectId: 'bogus',
-      });
-    client.auth.getProjectId = sinon.stub().resolves(fakeProjectId);
-    const result = await client.getProjectId();
-    assert.strictEqual(result, fakeProjectId);
-    assert((client.auth.getProjectId as SinonStub).calledWithExactly());
-  });
+    it('has getProjectId method', async () => {
+      const fakeProjectId = 'fake-project-id';
+      const client =
+        new cloudfilestoremanagerModule.v1.CloudFilestoreManagerClient({
+          credentials: {client_email: 'bogus', private_key: 'bogus'},
+          projectId: 'bogus',
+        });
+      client.auth.getProjectId = sinon.stub().resolves(fakeProjectId);
+      const result = await client.getProjectId();
+      assert.strictEqual(result, fakeProjectId);
+      assert((client.auth.getProjectId as SinonStub).calledWithExactly());
+    });
 
-  it('has getProjectId method with callback', async () => {
-    const fakeProjectId = 'fake-project-id';
-    const client =
-      new cloudfilestoremanagerModule.v1.CloudFilestoreManagerClient({
-        credentials: {client_email: 'bogus', private_key: 'bogus'},
-        projectId: 'bogus',
-      });
-    client.auth.getProjectId = sinon
-      .stub()
-      .callsArgWith(0, null, fakeProjectId);
-    const promise = new Promise((resolve, reject) => {
-      client.getProjectId((err?: Error | null, projectId?: string | null) => {
-        if (err) {
-          reject(err);
-        } else {
-          resolve(projectId);
-        }
+    it('has getProjectId method with callback', async () => {
+      const fakeProjectId = 'fake-project-id';
+      const client =
+        new cloudfilestoremanagerModule.v1.CloudFilestoreManagerClient({
+          credentials: {client_email: 'bogus', private_key: 'bogus'},
+          projectId: 'bogus',
+        });
+      client.auth.getProjectId = sinon
+        .stub()
+        .callsArgWith(0, null, fakeProjectId);
+      const promise = new Promise((resolve, reject) => {
+        client.getProjectId((err?: Error | null, projectId?: string | null) => {
+          if (err) {
+            reject(err);
+          } else {
+            resolve(projectId);
+          }
+        });
       });
+      const result = await promise;
+      assert.strictEqual(result, fakeProjectId);
     });
-    const result = await promise;
-    assert.strictEqual(result, fakeProjectId);
   });
 
   describe('getInstance', () => {
diff --git a/packages/google-cloud-filestore/test/gapic_cloud_filestore_manager_v1beta1.ts b/packages/google-cloud-filestore/test/gapic_cloud_filestore_manager_v1beta1.ts
index 06c84e5da31..b7eced66804 100644
--- a/packages/google-cloud-filestore/test/gapic_cloud_filestore_manager_v1beta1.ts
+++ b/packages/google-cloud-filestore/test/gapic_cloud_filestore_manager_v1beta1.ts
@@ -145,111 +145,113 @@ function stubAsyncIterationCall<ResponseType>(
 }
 
 describe('v1beta1.CloudFilestoreManagerClient', () => {
-  it('has servicePath', () => {
-    const servicePath =
-      cloudfilestoremanagerModule.v1beta1.CloudFilestoreManagerClient
-        .servicePath;
-    assert(servicePath);
-  });
+  describe('Common methods', () => {
+    it('has servicePath', () => {
+      const servicePath =
+        cloudfilestoremanagerModule.v1beta1.CloudFilestoreManagerClient
+          .servicePath;
+      assert(servicePath);
+    });
 
-  it('has apiEndpoint', () => {
-    const apiEndpoint =
-      cloudfilestoremanagerModule.v1beta1.CloudFilestoreManagerClient
-        .apiEndpoint;
-    assert(apiEndpoint);
-  });
+    it('has apiEndpoint', () => {
+      const apiEndpoint =
+        cloudfilestoremanagerModule.v1beta1.CloudFilestoreManagerClient
+          .apiEndpoint;
+      assert(apiEndpoint);
+    });
 
-  it('has port', () => {
-    const port =
-      cloudfilestoremanagerModule.v1beta1.CloudFilestoreManagerClient.port;
-    assert(port);
-    assert(typeof port === 'number');
-  });
+    it('has port', () => {
+      const port =
+        cloudfilestoremanagerModule.v1beta1.CloudFilestoreManagerClient.port;
+      assert(port);
+      assert(typeof port === 'number');
+    });
 
-  it('should create a client with no option', () => {
-    const client =
-      new cloudfilestoremanagerModule.v1beta1.CloudFilestoreManagerClient();
-    assert(client);
-  });
+    it('should create a client with no option', () => {
+      const client =
+        new cloudfilestoremanagerModule.v1beta1.CloudFilestoreManagerClient();
+      assert(client);
+    });
 
-  it('should create a client with gRPC fallback', () => {
-    const client =
-      new cloudfilestoremanagerModule.v1beta1.CloudFilestoreManagerClient({
-        fallback: true,
-      });
-    assert(client);
-  });
+    it('should create a client with gRPC fallback', () => {
+      const client =
+        new cloudfilestoremanagerModule.v1beta1.CloudFilestoreManagerClient({
+          fallback: true,
+        });
+      assert(client);
+    });
 
-  it('has initialize method and supports deferred initialization', async () => {
-    const client =
-      new cloudfilestoremanagerModule.v1beta1.CloudFilestoreManagerClient({
-        credentials: {client_email: 'bogus', private_key: 'bogus'},
-        projectId: 'bogus',
-      });
-    assert.strictEqual(client.cloudFilestoreManagerStub, undefined);
-    await client.initialize();
-    assert(client.cloudFilestoreManagerStub);
-  });
+    it('has initialize method and supports deferred initialization', async () => {
+      const client =
+        new cloudfilestoremanagerModule.v1beta1.CloudFilestoreManagerClient({
+          credentials: {client_email: 'bogus', private_key: 'bogus'},
+          projectId: 'bogus',
+        });
+      assert.strictEqual(client.cloudFilestoreManagerStub, undefined);
+      await client.initialize();
+      assert(client.cloudFilestoreManagerStub);
+    });
 
-  it('has close method for the initialized client', done => {
-    const client =
-      new cloudfilestoremanagerModule.v1beta1.CloudFilestoreManagerClient({
-        credentials: {client_email: 'bogus', private_key: 'bogus'},
-        projectId: 'bogus',
+    it('has close method for the initialized client', done => {
+      const client =
+        new cloudfilestoremanagerModule.v1beta1.CloudFilestoreManagerClient({
+          credentials: {client_email: 'bogus', private_key: 'bogus'},
+          projectId: 'bogus',
+        });
+      client.initialize();
+      assert(client.cloudFilestoreManagerStub);
+      client.close().then(() => {
+        done();
       });
-    client.initialize();
-    assert(client.cloudFilestoreManagerStub);
-    client.close().then(() => {
-      done();
     });
-  });
 
-  it('has close method for the non-initialized client', done => {
-    const client =
-      new cloudfilestoremanagerModule.v1beta1.CloudFilestoreManagerClient({
-        credentials: {client_email: 'bogus', private_key: 'bogus'},
-        projectId: 'bogus',
+    it('has close method for the non-initialized client', done => {
+      const client =
+        new cloudfilestoremanagerModule.v1beta1.CloudFilestoreManagerClient({
+          credentials: {client_email: 'bogus', private_key: 'bogus'},
+          projectId: 'bogus',
+        });
+      assert.strictEqual(client.cloudFilestoreManagerStub, undefined);
+      client.close().then(() => {
+        done();
       });
-    assert.strictEqual(client.cloudFilestoreManagerStub, undefined);
-    client.close().then(() => {
-      done();
     });
-  });
 
-  it('has getProjectId method', async () => {
-    const fakeProjectId = 'fake-project-id';
-    const client =
-      new cloudfilestoremanagerModule.v1beta1.CloudFilestoreManagerClient({
-        credentials: {client_email: 'bogus', private_key: 'bogus'},
-        projectId: 'bogus',
-      });
-    client.auth.getProjectId = sinon.stub().resolves(fakeProjectId);
-    const result = await client.getProjectId();
-    assert.strictEqual(result, fakeProjectId);
-    assert((client.auth.getProjectId as SinonStub).calledWithExactly());
-  });
+    it('has getProjectId method', async () => {
+      const fakeProjectId = 'fake-project-id';
+      const client =
+        new cloudfilestoremanagerModule.v1beta1.CloudFilestoreManagerClient({
+          credentials: {client_email: 'bogus', private_key: 'bogus'},
+          projectId: 'bogus',
+        });
+      client.auth.getProjectId = sinon.stub().resolves(fakeProjectId);
+      const result = await client.getProjectId();
+      assert.strictEqual(result, fakeProjectId);
+      assert((client.auth.getProjectId as SinonStub).calledWithExactly());
+    });
 
-  it('has getProjectId method with callback', async () => {
-    const fakeProjectId = 'fake-project-id';
-    const client =
-      new cloudfilestoremanagerModule.v1beta1.CloudFilestoreManagerClient({
-        credentials: {client_email: 'bogus', private_key: 'bogus'},
-        projectId: 'bogus',
-      });
-    client.auth.getProjectId = sinon
-      .stub()
-      .callsArgWith(0, null, fakeProjectId);
-    const promise = new Promise((resolve, reject) => {
-      client.getProjectId((err?: Error | null, projectId?: string | null) => {
-        if (err) {
-          reject(err);
-        } else {
-          resolve(projectId);
-        }
+    it('has getProjectId method with callback', async () => {
+      const fakeProjectId = 'fake-project-id';
+      const client =
+        new cloudfilestoremanagerModule.v1beta1.CloudFilestoreManagerClient({
+          credentials: {client_email: 'bogus', private_key: 'bogus'},
+          projectId: 'bogus',
+        });
+      client.auth.getProjectId = sinon
+        .stub()
+        .callsArgWith(0, null, fakeProjectId);
+      const promise = new Promise((resolve, reject) => {
+        client.getProjectId((err?: Error | null, projectId?: string | null) => {
+          if (err) {
+            reject(err);
+          } else {
+            resolve(projectId);
+          }
+        });
       });
+      const result = await promise;
+      assert.strictEqual(result, fakeProjectId);
     });
-    const result = await promise;
-    assert.strictEqual(result, fakeProjectId);
   });
 
   describe('getInstance', () => {