public int valence(Vertex v) {
		return (inValence(v) + outValence(v) - numLoops(v));
	}
The number of edges incident with v. For unweighted
  graphs valence and degree are the same, except valence is an int
 while degree is a double.
Ghidra/Framework/Generic/src/main/java/ghidra/util/graph/DirectedGraph.java