void visitNode(ProgramNode node) {
		node.visit();

		// see if any children were added (would happen due to a drag and drop operation if 
		// node had not been visited before the operation);
		// if child count > 0 then we have to make sure we aren't adding duplicates
		int nChildNodes = node.getChildCount();

		// add children to this node (has to be a Module)
		ProgramModule m = node.getModule();
		Group[] groups = m.getChildren();
		for (Group group : groups) {
			if (nChildNodes == 0 || !childGroupAdded(node, group)) {
				insertGroup(node, group, node.getChildCount());
			}
		}
	}
Set the GroupPath object in the given node.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/programtree/ProgramDnDTree.java