@NotNull

xml/dom-tests/tests/com/intellij/util/xml/DomReferencesTest.java

@@ -1,5 +1,17 @@
 /*
- * Copyright (c) 2000-2006 JetBrains s.r.o. All Rights Reserved.
+ * Copyright 2000-2015 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  */
 package com.intellij.util.xml;
 
@@ -236,11 +248,13 @@ public class DomReferencesTest extends DomHardCoreTestCase {
       return t == null ? null : t.toString();
     }
 
+    @NotNull
     @Override
-    public Collection<? extends StringBuffer> getVariants(final ConvertContext context) {
+    public Collection<StringBuffer> getVariants(final ConvertContext context) {
       return Arrays.asList(new StringBuffer("239"), new StringBuffer("42"), new StringBuffer("foo"));
     }
 
+    @NotNull
     @Override
     public Set<String> getAdditionalVariants() {
       return Collections.singleton("zzz");