int index(Edge e) {
		try {
			return edgeIndices.get(e.key());
		}
		catch (NoValueException exc) {
			return -1;
		}
	}
Returns the internal index of the given edge within this edge set.
 Throws a class cast exception if the object is not an edge.
Ghidra/Framework/Generic/src/main/java/ghidra/util/graph/EdgeSet.java