private void handleSymbolRemoved(ProgramChangeRecord rec) {
		Address address = rec.getStart();
		AttributedVertex vertex = getVertex(address);
		if (vertex == null) {
			return;
		}
		Symbol symbol = program.getSymbolTable().getPrimarySymbol(address);
		String displayName = symbol == null ? address.toString() : symbol.getName();
		graphDisplay.updateVertexName(vertex, displayName);
	}
Base class for GraphDisplay listeners whose nodes represent addresses.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/graph/AddressBasedGraphDisplayListener.java