protected String getVertexId(Address address) {
		// vertex ids for external locations use symbol names since they don't have meaningful addresses.
		if (address.isExternalAddress()) {
			Symbol s = symbolTable.getPrimarySymbol(address);
			return s.getName(true);
		}
		return address.toString();
	}
Base class for GraphDisplay listeners whose nodes represent addresses.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/graph/AddressBasedGraphDisplayListener.java