code: /*
   * Copyright 2012-2018 Chronicle Map Contributors
   *
   * 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 net.openhft.chronicle.map.impl;
  
  import net.openhft.chronicle.hash.Data;
  import net.openhft.chronicle.map.impl.ret.InstanceReturnValue;
  import org.jetbrains.annotations.NotNull;
  
  public final class NullReturnValue<V> implements InstanceReturnValue<V> {
  
      private static final NullReturnValue<?> NULL_RETURN_VALUE = new NullReturnValue<>();
  
      private NullReturnValue() {
      }
  
      @SuppressWarnings("unchecked")
      public static <V> InstanceReturnValue<V> get() {
          return (InstanceReturnValue<V>) NULL_RETURN_VALUE;
      }
  
      @Override
      public V returnValue() {
          return null;
      }
  
      @Override
      public void returnValue(@NotNull Data<V> value) {
          // ignore
      }
  }
  