| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 freemarker.core; |
| |
| import java.util.AbstractSet; |
| |
| /** Don't use this; used internally by FreeMarker, might changes without notice. */ |
| public abstract class _UnmodifiableSet<E> extends AbstractSet<E> { |
| |
| @Override |
| public boolean add(E o) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public boolean remove(Object o) { |
| if (contains(o)) { |
| throw new UnsupportedOperationException(); |
| } |
| return false; |
| } |
| |
| @Override |
| public void clear() { |
| if (!isEmpty()) { |
| throw new UnsupportedOperationException(); |
| } |
| } |
| |
| } |