/**
   * Returns the value associated with {@code key} in this cache, first loading that value if
   * necessary. No observable state associated with this cache is modified until loading completes.
   *
   * <p>If another call to {@link #get} or {@link #getUnchecked} is currently loading the value for
   * {@code key}, simply waits for that thread to finish and returns its loaded value. Note that

   * computation is {@linkplain java.util.concurrent.Future#isDone() complete} or, if the
   * computation is already complete, immediately.
   *
   * <p>The callback is run on {@code executor}. There is no guaranteed ordering of execution of
   * callbacks, but any callback added through this method is guaranteed to be called once the
   * computation is complete.
   *
   * <p>Example:
   *
   * <pre>{@code

    assertFalse(sleeper.completed);
    assertTrue(getUninterruptibly(delayedFuture));

    assertTrue(Thread.interrupted()); // clears the interrupt state, too
    assertTrue(sleeper.completed);
  }

  private static class SleepingRunnable implements Runnable {
    final int millis;
    volatile boolean completed;

    public SleepingRunnable(int millis) {

    this.future = future;

    future.addListener(this, directExecutor());
  }

  @Override
  public void run() {
    countDownLatch.countDown();
  }

  /**
   * Verify that the listener completes in a reasonable amount of time, and Asserts that the future
   * returns the expected data.
   *
   * @throws Throwable if the listener isn't called or if it resulted in a throwable or if the

  private static final String RESULT_DATA = "SUCCESS";

  private SettableFuture<String> outputFuture;
  // Signals that the function is waiting to complete
  private CountDownLatch funcIsWaitingLatch;
  // Signals the function so it will complete
  private CountDownLatch funcCompletionLatch;

  @Override
  protected ListenableFuture<String> buildChainingFuture(ListenableFuture<Integer> inputFuture) {

 */
public final class InternalFutures {
  /**
   * Usually returns {@code null} but, if the given {@code Future} has failed, may <i>optionally</i>
   * return the cause of the failure. "Failure" means specifically "completed with an exception"; it
   * does not include "was cancelled." To be explicit: If this method returns a non-null value,
   * then:
   *
   * <ul>
   *   <li>{@code isDone()} must return {@code true}

            }
          };
      for (int j = 0; j < 10; j++) {
        executor.execute(wrapper);
      }
      barrier.await(); // release the threads!
      barrier.await(); // wait for them all to complete
      assertEquals(1, task.get().intValue());
      assertEquals(1, counter.get());
    }
    executor.shutdown();
  }

  @J2ktIncompatible
  @GwtIncompatible // blocking wait

 * is not equivalent to the concatenation of their encoded form. Therefore, {@link
 * #putString(CharSequence, Charset)} should only be used consistently with <i>complete</i>
 * sequences and not broken into chunks.
 *
 * @author Kevin Bourrillion
 * @since 11.0
 */
@Beta
@ElementTypesAreNonnullByDefault
public interface Hasher extends PrimitiveSink {
  @CanIgnoreReturnValue

   * {@code null}; it may either return a non-null value or throw an exception.
   *
   * <p>No observable state associated with this cache is modified until loading completes.
   *
   * @throws ExecutionException if a checked exception was thrown while loading the value
   * @throws UncheckedExecutionException if an unchecked exception was thrown while loading the
   *     value

     *
     * <p>The thread's interrupt bit is cleared before execution of each task.
     *
     * <p>If the Thread in use is interrupted before or during execution of the tasks in {@link
     * #queue}, the Executor will complete its tasks, and then restore the interruption. This means
     * that once the Thread returns to the Executor that this Executor composes, the interruption