True if treeview leaves in this column use icons. In that case, you have
to pass Hollywood brushes/icons to use as icons to the Treeview.InsertLeaf method.
Note that this attribute only applies to treeview leaves. Treeview nodes can use
icons without setting any specific attribute. Icons for treeview nodes are always
available, but for leaves you have to set this attribute to True first.
Note that RapaGUI might scale the image to fit to the current monitor's DPI setting. Please read the chapter on high-DPI support for more information. See High-DPI support for details.
Please also read about RapaGUI's image cache to learn more about icon support in RapaGUI. See Image cache for details.
On AmigaOS and compatibles icon support is only available with MUI 4.0 or better.