void reorder(Group group, ProgramModule parentModule) {

		Group[] children = parentModule.getChildren();
		for (int i = 0; i < children.length; i++) {
			if (children[i].equals(group)) {
				reorder(group, parentModule, i);
				return;
			}
		}
	}
Called from the update thread to process a "module reordered" event.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/programtree/ProgramDnDTree.java