private AbstractTestVertex v(int id) {
		return vertex(id);
	}
Returns the edge for the given vertices, creating it if it does not yet exist.

@param v1 the start vertex
@param v2 the end vertex
@return the edge
Ghidra/Framework/Graph/src/test.slow/java/ghidra/graph/viewer/edge/VisualGraphPathHighlighterTest.java