@CanIgnoreReturnValue
    public boolean set(@CheckForNull V newValue) {
      return futureValue.set(newValue);
    }

    @CanIgnoreReturnValue
    public boolean setException(Throwable t) {
      return futureValue.setException(t);
    }

    private ListenableFuture<V> fullyFailedFuture(Throwable t) {
      return Futures.immediateFailedFuture(t);
    }

    @Override

    SettableFuture<String> f = SettableFuture.create();
    Exception e = new IllegalArgumentException("foo not found");
    MockCallback callback = new MockCallback(e);
    addCallback(f, callback, directExecutor());
    f.setException(e);
  }

  public void testCancel() {
    SettableFuture<String> f = SettableFuture.create();
    FutureCallback<String> callback =
        new FutureCallback<String>() {
          private boolean called = false;

    T fallbackResult;
    try {
      fallbackResult = doFallback(localFallback, castThrowable);
    } catch (Throwable t) {
      restoreInterruptIfIsInterruptedException(t);
      setException(t);
      return;
    } finally {
      exceptionType = null;
      fallback = null;
    }

    setResult(fallbackResult);
  }

  @Override
  @CheckForNull

    @CanIgnoreReturnValue
    public boolean set(@CheckForNull V newValue) {
      return futureValue.set(newValue);
    }

    @CanIgnoreReturnValue
    public boolean setException(Throwable t) {
      return futureValue.setException(t);
    }

    private ListenableFuture<V> fullyFailedFuture(Throwable t) {
      return Futures.immediateFailedFuture(t);
    }

    @Override