content: /*
   * 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 org.apache.beam.sdk.transforms.windowing;
  
  /**
   * Abstract base class for {@link WindowFn WindowFns} that do not merge windows.
   *
   * @param <T> type of elements being windowed
   * @param <W> {@link BoundedWindow} subclass used to represent the windows used by this {@code
   *     WindowFn}
   */
  public abstract class NonMergingWindowFn<T, W extends BoundedWindow> extends WindowFn<T, W> {
    @Override
    public final void mergeWindows(MergeContext c) {}
  
    @Override
    public final boolean isNonMerging() {
      return true;
    }
  }
  