ow the observer widget is not repeated again.

\image html tree_docs_uncategorized_tree.jpg "Tree With Categorized Leaf Nodes"

The actual implementation is show below:

\code
TreeNode* rootNode = new TreeNode("Root");
TreeNode* parentNode1 = rootNode->addNode("Parent 1");
TreeNode* parentNode2 = rootNode->addNode("Parent 2");
parentNode1->addItem("Child 1");
parentNode1->addItem("Child 2");
parentNode2->addItem("Child 3");
parentNode2->addItem("Child 4");
parentNode2->addItem("Child 5");
\endcode

It is cl