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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *     http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  
18  package org.apache.commons.pipeline.validation;
19  
20  import java.lang.annotation.ElementType;
21  import java.lang.annotation.Retention;
22  import java.lang.annotation.RetentionPolicy;
23  import java.lang.annotation.Target;
24  
25  import org.apache.commons.pipeline.Stage;
26  
27  /**
28   * This marker annotation indicates that the {@link Stage} produces the same type
29   * of object that is consumed (or any subtype thereof). This is used to allow
30   * correct resolution of stage compatibility between different parts of a
31   * pipeline when there are intervening generic pass-through stages such
32   * as loggers, which can consume any type of object and produce the
33   * same object unchanged.
34   *
35   * This annotation is used in lieu of the {@link Production} annotaion
36   * and overrides it if both are present.
37   *
38   *
39   */
40  @Target(ElementType.TYPE)
41  @Retention(RetentionPolicy.RUNTIME)
42  public @interface ProducesConsumed { }