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.options;
  
  /**
   * An interface used with the {@link Default.InstanceFactory} annotation to specify the class that
   * will be an instance factory to produce default values for a given getter on {@link
   * PipelineOptions}. When a property on a {@link PipelineOptions} is fetched, and is currently
   * unset, the default value factory will be instantiated and invoked.
   *
   * <p>Care must be taken to not produce an infinite loop when accessing other fields on the {@link
   * PipelineOptions} object.
   *
   * @param <T> The type of object this factory produces.
   */
  public interface DefaultValueFactory<T> {
    /**
     * Creates a default value for a getter marked with {@link Default.InstanceFactory}.
     *
     * @param options The current pipeline options.
     * @return The default value to be used for the annotated getter.
     */
    T create(PipelineOptions options);
  }
  