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.extensions.euphoria.core.client.util;
  
  import java.util.Comparator;
  import org.apache.beam.sdk.extensions.euphoria.core.annotation.audience.Audience;
  import org.apache.beam.sdk.extensions.euphoria.core.client.functional.CombinableReduceFunction;
  import org.apache.beam.sdk.extensions.euphoria.core.client.functional.UnaryFunction;
  
  /**
   * Calculate maximum.
   *
   * @deprecated Use Java SDK directly, Euphoria is scheduled for removal in a future release.
   */
  @Audience(Audience.Type.CLIENT)
  @Deprecated
  public class Max {
  
    private Max() {}
  
    /**
     * Return {@code CombinableReduceFunction} to calculate maximum of input.
     *
     * @param <InputT> the type of elements handled
     * @param <X> the type of key by which to compare the elements
     * @param extract the key extraction function
     * @return a combiner function which delivers the "maximum" element seen; never {@code null}
     */
    public static <InputT, X extends Comparable<X>> CombinableReduceFunction<InputT> of(
        UnaryFunction<InputT, X> extract) {
  
      return values ->
          values
              .max(Comparator.comparing(extract::apply))
              .orElseThrow(() -> new IllegalStateException("Got empty stream on input!"));
    }
  }
  