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.kafka.connect.util;
  
  /**
   * Generic interface for callbacks
   */
  @FunctionalInterface
  public interface Callback<V> {
      /**
       * Invoked upon completion of the operation.
       *
       * @param error the error that caused the operation to fail, or null if no error occurred
       * @param result the return value, or null if the operation failed
       */
      void onCompletion(Throwable error, V result);
  
      default void recordStage(Stage stage) {
      }
  
      default <V2> Callback<V2> chainStaging(Callback<V2> chained) {
          return new Callback<>() {
              @Override
              public void recordStage(Stage stage) {
                  Callback.this.recordStage(stage);
              }
  
              @Override
              public void onCompletion(Throwable error, V2 result) {
                  chained.onCompletion(error, result);
              }
          };
      }
  
  }
  