Fix unused type compiler warnings

spring-core/src/main/java/org/springframework/core/io/support/PathMatchingResourcePatternResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2013 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -658,6 +658,7 @@ public class PathMatchingResourcePatternResolver implements ResourcePatternResol
 	/**
 	 * VFS visitor for path matching purposes.
 	 */
+	@SuppressWarnings("unused")
 	private static class PatternVirtualFileVisitor implements InvocationHandler {
 
 		private final String subPattern;