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.calcite.rel.metadata;
  
  import net.bytebuddy.ByteBuddy;
  import net.bytebuddy.description.modifier.SyntheticState;
  import net.bytebuddy.description.modifier.Visibility;
  import net.bytebuddy.dynamic.loading.ClassLoadingStrategy;
  import net.bytebuddy.implementation.FixedValue;
  
  /**
   * Constructs {@link MetadataHandler} classes useful for tests.
   */
  class TestMetadataHandlers {
    /**
     * Returns a class representing an interface extending {@link MetadataHandler} and having
     * a synthetic method.
     *
     * @return MetadataHandler class with a synthetic method
     */
    static Class<? extends MetadataHandler<TestMetadata>> handlerClassWithSyntheticMethod() {
      return new ByteBuddy()
          .redefine(BlankMetadataHandler.class)
          .defineMethod("syntheticMethod", Void.class, SyntheticState.SYNTHETIC, Visibility.PUBLIC)
          .intercept(FixedValue.nullValue())
          .make()
          .load(TestMetadataHandlers.class.getClassLoader(), ClassLoadingStrategy.Default.CHILD_FIRST)
          .getLoaded();
    }
  
    private TestMetadataHandlers() {
      // prevent instantiation
    }
  
    /**
     * A blank {@link MetadataHandler} that is used as a base for adding a synthetic method.
     */
    private interface BlankMetadataHandler extends MetadataHandler<TestMetadata> {
    }
  }
  