* ClosingFuture} pipeline.
   *
   * @param <V> the type of the final value of a successful pipeline
   * @see ClosingFuture#finishToValueAndCloser(ValueAndCloserConsumer, Executor)
   */
  public interface ValueAndCloserConsumer<V extends @Nullable Object> {

    /** Accepts a {@link ValueAndCloser} for the last step in a {@link ClosingFuture} pipeline. */
    void accept(ValueAndCloser<V> valueAndCloser);

   * ClosingFuture} pipeline.
   *
   * @param <V> the type of the final value of a successful pipeline
   * @see ClosingFuture#finishToValueAndCloser(ValueAndCloserConsumer, Executor)
   */
  @FunctionalInterface
  public interface ValueAndCloserConsumer<V extends @Nullable Object> {

    /** Accepts a {@link ValueAndCloser} for the last step in a {@link ClosingFuture} pipeline. */

import com.google.common.util.concurrent.ClosingFuture.Peeker;
import com.google.common.util.concurrent.ClosingFuture.ValueAndCloser;
import com.google.common.util.concurrent.ClosingFuture.ValueAndCloserConsumer;
import java.io.Closeable;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;