static CppCompositeType createI_syntactic_struct32(VxtManager vxtManager,
			CppCompositeType G_struct, CppCompositeType H_struct, CppCompositeType C_struct) {
		CppCompositeType I_struct = createStruct32("I", 0);
		try {
			if (C_struct == null) {
				C_struct = createC_struct32(vxtManager);
			}
			// Could be problem if only one of G or H is null: won't have same C.
			if (G_struct == null) {
				G_struct = createG_struct32(vxtManager, C_struct);
			}
			if (H_struct == null) {
				H_struct = createH_struct32(vxtManager, C_struct);
			}
			I_struct.addDirectSyntacticBaseClass(G_struct.getComposite(), G_struct);
			I_struct.addDirectSyntacticBaseClass(H_struct.getComposite(), H_struct);
			I_struct.addMember("i1", intT, false, 0);
		}
		catch (Exception e) {
			String msg = "Error in static initialization of test: " + e;
			Msg.error(null, msg);
			throw new AssertException(msg);
		}
		return I_struct;
	}
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