@NotNull
  private CancellablePromise<Node> computeTreeDataOnBgt(@NotNull Command command) {
    if (command.canRunAsync()) {
      return background.computeAsync(command::computeAsync);
    }
    return background.compute(command::computeNode);
  }
@NotNull
  private CancellablePromise<Node> computeTreeDataOnBgt(@NotNull Command command)