private TestEdge edge(AbstractTestVertex v1, AbstractTestVertex v2) {
		//
		// First, find the exact instance of the edge in the graph, as it may have state 
		// applied to it that we need to verify for testing.
		//
		TestEdge e = graph.findEdge(v1, v2);

		if (graph.containsEdge(e)) {
			return e;
		}

		e = new TestEdge(v1, v2);
		graph.addEdge(e);
		return e;
	}
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