private void checkExpanded() {
    var childCount = model.getChildCount(path.getLastPathComponent());
    if (childCount > 1) { // Definitely more than just the 'loading...' node.
      finishMeasuring();
    }
    else if (childCount == 1) {
      var child = model.getChild(path.getLastPathComponent(), 0);
      if (child instanceof LoadingNode) {
        ensureSubscribedToModel(); // Need to wait for async load.
      }
      else {
        finishMeasuring();
      }
    }
  }
private void checkExpanded()