if (!state.permitsPublicUserToTransitionTo(State.CANCELLED)) {
      return false;
    }

    this.mayInterruptIfRunning = mayInterruptIfRunning;
    state = State.CANCELLED;
    notifyAndClearListeners();

    if (delegate != null) {
      // TODO(lukes): consider adding the StackOverflowError protection from the server version
      delegate.cancel(mayInterruptIfRunning);
    }

    return true;