@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 immediateFailedFuture(t);
    }

    @Override