Method setException

output/java_guava/1.4.19/AbstractFuture.java:657–665

Sets the failed result of this Future unless this Future has already been cancelled or set (including plain #setFuture set asynchronously). When a call to this method returns, the Future is guaranteed to be plain #isDone done only if the call was accepted

(Throwable throwable)

   */

  @CanIgnoreReturnValue
  protected boolean setException(Throwable throwable) {
    Object valueToSet = new Failure(checkNotNull(throwable));
    if (ATOMIC_HELPER.casValue(this, null, valueToSet)) {
      complete();
      return true;
    }
    return false;
  }

  /**
   * Sets the result of this {@code Future} to match the supplied input {@code Future} once the