@Test
	public void testNoCyclicDependencyProblemForStructurePointer() {
		Pointer unionPointer = createPointer(union, 4);
		try {
			union.add(unionPointer);
		}
		catch (IllegalArgumentException e) {
			Assert.fail("Should be able to add a union pointer to the pointer's union.");
		}
		try {
			union.insert(0, unionPointer);
		}
		catch (IllegalArgumentException e) {
			e.printStackTrace();
			Assert.fail("Should be able to insert a union pointer into the pointer's union.");
		}
	}
Test that a structure can contain a pointer in it to the same structure.
Ghidra/Framework/SoftwareModeling/src/test/java/ghidra/program/database/data/UnionDBTest.java