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.runners.dataflow.worker.windmill.state;
  
  import java.util.List;
  import org.apache.beam.sdk.util.Weighted;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.annotations.VisibleForTesting;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.ForwardingList;
  
  @VisibleForTesting
  public class WeightedList<T> extends ForwardingList<T> implements Weighted {
    private final List<T> delegate;
    long weight;
  
    WeightedList(List<T> delegate) {
      this.delegate = delegate;
      this.weight = 0;
    }
  
    @Override
    protected List<T> delegate() {
      return delegate;
    }
  
    @Override
    public boolean add(T elem) {
      throw new UnsupportedOperationException("Must use AddWeighted()");
    }
  
    @Override
    public long getWeight() {
      return weight;
    }
  
    public void addWeighted(T elem, long weight) {
      delegate.add(elem);
      this.weight += weight;
    }
  }
  