/*
 * 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.tsfile.external.commons.io.function;

import java.util.Objects;
import java.util.stream.BaseStream;

/**
 * Abstracts an {@link IOBaseStream} implementation.
 *
 * <p>Keep package-private for now.
 *
 * @param <T> the type of the stream elements.
 * @param <S> the type of the stream extending {@code IOBaseStream}.
 */
abstract class IOBaseStreamAdapter<T, S extends IOBaseStream<T, S, B>, B extends BaseStream<T, B>>
    implements IOBaseStream<T, S, B> {

  /** The underlying base stream. */
  private final B delegate;

  /**
   * Constructs an instance.
   *
   * @param delegate the delegate.
   */
  IOBaseStreamAdapter(final B delegate) {
    this.delegate = Objects.requireNonNull(delegate, "delegate");
  }

  @Override
  public B unwrap() {
    return delegate;
  }
}
