void reloadTree(ProgramDnDTree tree) {
		reloadTree(tree, false);
	}
The program was restored from an Undo/Redo operation so reload it

@param checkRoot if true, only rebuild the tree if the root node is invalid; if false,
       force a rebuild of the tree
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/programtree/ProgramTreePlugin.java