private void assertEmptyTree() {
		final GTreeNode rootNode = tree.getViewRoot();
		final Integer[] box = new Integer[1];
		runSwing(() -> box[0] = rootNode.getChildCount());
		assertEquals("Root node is not empty as expected", 0, (int) box[0]);
	}
Tests for managing categories through the data manager plugin and tests for
actions being enabled when a node is selected.
Ghidra/Features/Base/src/test.slow/java/ghidra/app/plugin/core/datamgr/DataTypeManagerPluginTest.java