return;
      }

      /*
       * Almost everything in GWT is an AbstractFuture (which is as good as TrustedFuture under
       * GWT). But ImmediateFuture and UncheckedThrowingFuture aren't, so we still need this case.
       */
      try {
        forceSet(getDone(delegate));
      } catch (ExecutionException exception) {
        forceSetException(exception.getCause());

        return; // give up if someone is calling complete
      }
      Waiter succ;
      while (curr != null) {
        succ = curr.next;
        if (curr.thread != null) { // we aren't unlinking this node, update pred.
          pred = curr;
        } else if (pred != null) { // We are unlinking this node and it has a predecessor.
          pred.next = succ;