ny observer widgets displaying it.

\code
// We can also delete all objects in the tree like this:
rootNode->deleteAll();

// If we want to remove all objects from the tree but we don't want to delete them we do this:
rootNode->detachAll();
\endcode

Note that \p rootNode will still have its objects attached to them after the \p detachAll() call. It is important to avoid memory leaks when detaching objects, thus you must then manually manage the lifetime. See \ref object_lifetimes for more information on th