private Container findContainer(Container parent, Class<?> theClass) {
		Component[] c = parent.getComponents();
		for (Component element : c) {
			if (theClass.isAssignableFrom(element.getClass())) {
				return (Container) element;
			}
			if (element instanceof Container) {
				Container container = findContainer((Container) element, theClass);
				if (container != null) {
					return container;
				}
			}
		}
		return null;
	}
{@link AbstractEnumEditorUndoRedoTest} contains tests which should be applied to the various 
{@link DataTypeManager} implementations which are responsible for setting {@code dtm} during
the setUp phase.
Ghidra/Features/Base/src/test.slow/java/ghidra/app/plugin/core/datamgr/editor/AbstractEnumEditorUndoRedoTest.java