private PNode getOrAddBranch(String branchName) {
			PNode node = getBranch(branchName);
			if (node != null) {
				return node;
			}
			node = new PNode(branchName);
			branches.add(node);
			return node;
		}
Class used for collecting owner and parentage information for vxtptrs (and maybe base
classes... in the future).  Used for creating a tree of information that is used for
determining shortened MSFT parentage.
Ghidra/Features/PDB/src/main/java/ghidra/app/util/pdb/pdbapplicator/CppCompositeType.java