protected void copyVertex(Vertex node, DirectedGraph other) {
		add(node);
		if (other != null) {
			copyVertexAttributeValues(node, other);
		}
	}
This method copies a vertex and all object attributes from graph 
'other' into this graph. 
@param node
@param other
Ghidra/Framework/Generic/src/main/java/ghidra/util/graph/DirectedGraph.java