docs: void firePropertyChildAdded(TreeNodeAddedEvent event) {
  		if (this.nodeListeners != null) {
  			for (final TreeNodeListener listener : this.nodeListeners) {
  				if (listener != null) {
  					listener.treeNodeChildAdded(event);
  				}
  			}
  		}
  		final N parentNode = getParentNode();
  		assert parentNode != this;
  		if (parentNode != null) {
  			parentNode.firePropertyChildAdded(event);
  		}
  	}