private PickedState<FGVertex> getPickedState() {
		FGComponent functionGraphViewer = getGraphComponent();
		VisualizationViewer<FGVertex, FGEdge> primaryViewer =
			functionGraphViewer.getPrimaryViewer();
		return primaryViewer.getPickedVertexState();
	}
Finds an edge that represents the given edge, which may no longer exist with
the same (==) edge instances.
Ghidra/Features/FunctionGraph/src/test.slow/java/ghidra/app/plugin/core/functiongraph/AbstractFunctionGraphTest.java