diff --git a/composer.lock b/composer.lock
new file mode 100644
index 0000000..67b65d8
--- /dev/null
+++ b/composer.lock
@@ -0,0 +1,76 @@
+{
+    "_readme": [
+        "This file locks the dependencies of your project to a known state",
+        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
+        "This file is @generated automatically"
+    ],
+    "content-hash": "48b2dfd16947ec5d25795c3fa6b35da4",
+    "packages": [
+        {
+            "name": "smarty/smarty",
+            "version": "dev-master",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/smarty-php/smarty.git",
+                "reference": "4b29dfce1195b04ee337d943a9c539c8d8eb5690"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/smarty-php/smarty/zipball/4b29dfce1195b04ee337d943a9c539c8d8eb5690",
+                "reference": "4b29dfce1195b04ee337d943a9c539c8d8eb5690",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=5.2"
+            },
+            "require-dev": {
+                "phpunit/phpunit": "6.4.1"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "3.1.x-dev"
+                }
+            },
+            "autoload": {
+                "classmap": [
+                    "libs/"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "LGPL-3.0"
+            ],
+            "authors": [
+                {
+                    "name": "Monte Ohrt",
+                    "email": "monte@ohrt.com"
+                },
+                {
+                    "name": "Uwe Tews",
+                    "email": "uwe.tews@googlemail.com"
+                },
+                {
+                    "name": "Rodney Rehm",
+                    "email": "rodney.rehm@medialize.de"
+                }
+            ],
+            "description": "Smarty - the compiling PHP template engine",
+            "homepage": "http://www.smarty.net",
+            "keywords": [
+                "templating"
+            ],
+            "time": "2020-01-27T15:08:35+00:00"
+        }
+    ],
+    "packages-dev": [],
+    "aliases": [],
+    "minimum-stability": "stable",
+    "stability-flags": {
+        "smarty/smarty": 20
+    },
+    "prefer-stable": false,
+    "prefer-lowest": false,
+    "platform": [],
+    "platform-dev": []
+}
diff --git a/testcase.php b/testcase.php
index 0e7895e..67f489a 100644
--- a/testcase.php
+++ b/testcase.php
@@ -2,8 +2,28 @@
 
 require_once __DIR__ . '/smarty-config.php';
 
+class SvgImage {
+    public function render($params, $smarty) {
+        $params += [
+            'id' => null,
+            'class' => null,
+            'style' => null,
+            'fallback' => null,
+        ];
+        return "\$" . __CLASS__ . " = " . var_export($params, true);
+    }
+}
+
+$smarty->registerPlugin('function', 'svgImage', [new SvgImage('/img/cat/icon'), 'render'], true, [
+    'name', 'id', 'class', 'style', 'fallback'
+]);
+
 $smarty->display(__FILE__);
 
 __HALT_COMPILER();
-?>PHP: {$smarty.const.PHP_VERSION}
+?>{svgImage name="icon"}
+
+{svgImage name="icon" id="id" class="none" style="float: left;" fallback="text"}
+
+PHP: {$smarty.const.PHP_VERSION}
 Smarty: {$smarty.version}