fix

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/proxy/branches/version-2.0-work@1520907 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/core/src/test/java/org/apache/commons/proxy2/util/SuffixInterceptor.java b/core/src/test/java/org/apache/commons/proxy2/util/SuffixInterceptor.java
index 899317d..466925e 100644
--- a/core/src/test/java/org/apache/commons/proxy2/util/SuffixInterceptor.java
+++ b/core/src/test/java/org/apache/commons/proxy2/util/SuffixInterceptor.java
@@ -49,6 +49,11 @@
 

     public Object intercept( Invocation methodInvocation ) throws Throwable

     {

-        return methodInvocation.proceed() + suffix;

+    	Object result = methodInvocation.proceed();

+    	if (result instanceof String)

+    	{

+    		result = ((String) result) + suffix;

+    	}

+    	return result;

     }

 }