private void undo(boolean doWait) throws Exception {
		Runnable r = () -> {
			try {
				undo();
				dtm.flushEvents();
			}
			catch (Exception e) {
				Assert.fail(e.getMessage());
			}
		};
		if (doWait) {
			runSwing(r);
		}
		else {
			runSwingLater(r);
		}
		waitForSwing();
	}
{@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