code: /*
   * Copyright (c) 2016-present, RxJava Contributors.
   *
   * Licensed 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 io.reactivex.rxjava3.parallel;
  
  import io.reactivex.rxjava3.annotations.NonNull;
  
  /**
   * Convenience interface and callback used by the {@link ParallelFlowable#to} operator to turn a ParallelFlowable into
   * another value fluently.
   * <p>History: 2.1.7 - experimental
   * @param <T> the upstream type
   * @param <R> the output type
   * @since 2.2
   */
  @FunctionalInterface
  public interface ParallelFlowableConverter<T, R> {
      /**
       * Applies a function to the upstream ParallelFlowable and returns a converted value of type {@code R}.
       *
       * @param upstream the upstream ParallelFlowable instance
       * @return the converted value
       */
      @NonNull
      R apply(@NonNull ParallelFlowable<T> upstream);
  }
  