}

          case CANCELLED:
          case INTERRUPTED:
            throw cancellationExceptionWithCause("Task was cancelled.", exception);

          default:
            throw new IllegalStateException("Error, synchronizer in invalid state: " + state);
        }
      }

      /** Checks if the state is {@link #COMPLETED}, {@link #CANCELLED}, or {@link #INTERRUPTED}. */
      boolean isDone() {

            }

          case CANCELLED:
          case INTERRUPTED:
            throw cancellationExceptionWithCause("Task was cancelled.", exception);

          default:
            throw new IllegalStateException("Error, synchronizer in invalid state: " + state);
        }
      }

      /** Checks if the state is {@link #COMPLETED}, {@link #CANCELLED}, or {@link #INTERRUPTED}. */
      boolean isDone() {

      // before the cancelled future completes, it will synchronously complete both the newFuture
      // from the cancelled operation and its own. This can cause one runnable to queue two tasks,
      // breaking the invariant this method relies on to iteratively run the next task after the
      // previous one completes.
      if (get() == RunningState.CANCELLED) {
        delegate = null;
        sequencer = null;

   * <p>If the call {@code setFuture(delegate)} is accepted and this {@code Future} is later
   * cancelled, cancellation will be propagated to {@code delegate}. Additionally, any call to
   * {@code setFuture} after any cancellation will propagate cancellation to the supplied {@code
   * Future}.
   *
   * <p>Note that, even if the supplied future is cancelled and it causes this future to complete,

   * input future and that of the future returned by the chain function. That is, if the returned
   * {@code Future} is cancelled, it will attempt to cancel the other two, and if either of the
   * other two is cancelled, the returned {@code Future} will receive a callback in which it will
   * attempt to cancel itself.
   *

      return;
    }

    /*
     * Any of the setException() calls below can fail if the output Future is cancelled between now
     * and then. This means that we're silently swallowing an exception -- maybe even an Error. But
     * this is no worse than what FutureTask does in that situation. Additionally, because the
     * Future was cancelled, its listeners have been run, so its consumers will not hang.
     *

    // stop it.
    blockingCallable.waitForStart();

    // This time, cancel the future for the first task. The task remains running, only the future
    // is cancelled.
    future1.cancel(false);

    // Give the second task a chance to (incorrectly) start up while the first task is running.
    // (This is the assertion that fails.)
    assertThat(future2.isDone()).isFalse();

  }

  public void testToString_cancelled() throws Exception {
    assertThat(immediateCancelledFuture().toString()).matches("[^\\[]+\\[status=CANCELLED\\]");
  }

  public void testToString_failed() {
    assertThat(immediateFailedFuture(new RuntimeException("foo")).toString())

    // stop it.
    blockingCallable.waitForStart();

    // This time, cancel the future for the first task. The task remains running, only the future
    // is cancelled.
    future1.cancel(false);

    // Give the second task a chance to (incorrectly) start up while the first task is running.
    // (This is the assertion that fails.)
    assertThat(future2.isDone()).isFalse();

        this.scheduledDelegate = scheduledDelegate;
      }

      @Override
      public boolean cancel(boolean mayInterruptIfRunning) {
        boolean cancelled = super.cancel(mayInterruptIfRunning);
        if (cancelled) {
          // Unless it is cancelled, the delegate may continue being scheduled
          scheduledDelegate.cancel(mayInterruptIfRunning);

          /*