Avoid compile warning using @SuppressWarnings(unused) on test case #1258

Author: kazuki43zoo

src/test/java/org/apache/ibatis/submitted/member_access/MemberAccessTest.java

@@ -334,6 +334,7 @@ public String getPublicProperty() {
     }
   }
 
+  @SuppressWarnings("unused")
   static class Bean {
     private String privateField;
     String packagePrivateField;
@@ -358,6 +359,7 @@ public void setPublicProperty(String value) {
     }
   }
 
+  @SuppressWarnings("unused")
   static class Immutable {
     private Map<String, String> properties = new HashMap<>();