static CppCompositeType createG1_struct32(VxtManager vxtManager, CppCompositeType C_struct,
			CppCompositeType E_struct) {
		try {
			CppCompositeType G1_struct = createStruct32("G1", 16);
			G1_struct.addDirectVirtualBaseClass(C_struct.getComposite(), C_struct, 0,
				ClassUtils.VXPTR_TYPE, 1);
			G1_struct.addDirectVirtualBaseClass(E_struct.getComposite(), E_struct, 0,
				ClassUtils.VXPTR_TYPE, 2);
			G1_struct.addMember("g11", intT, false, 4);
			return G1_struct;
		}
		catch (Exception e) {
			String msg = "Error in static initialization of test: " + e;
			Msg.error(null, msg);
			throw new AssertException(msg);
		}
	}
This is not part of the DataTypeManager API... it is only for testing when needing
 to clear results because of another run that creates the same-named types
Ghidra/Features/PDB/src/test/java/ghidra/app/util/pdb/pdbapplicator/CppCompositeTypeTest.java