if (delegate == null) {
        return;
      }

      /*
       * If we're about to complete the TimeoutFuture, we want to release our reference to it.
       * Otherwise, we'll pin it (and its result) in memory until the timeout task is GCed. (The
       * need to clear our reference to the TimeoutFuture is the reason we use a *static* nested
       * class with a manual reference back to the "containing" class.)