protected boolean checkForEdge(MouseEvent e) {
		if (!checkModifiers(e) || isOverVertex(e)) {
			selectedEdge = null;
			return false;
		}

		VisualizationViewer<V, E> vv = getViewer(e);
		selectedEdge = JgtUtils.getEdge(e, vv);
		if (selectedEdge == null) {
			return false;
		}

		e.consume();
		isHandlingMouseEvents = true;
		return true;
	}
Checks the given mouse event to see if it is a valid event for selecting an edge at the
mouse location.  If so, then the edge is selected in this mouse handler and the event
is consumed.
@param e the event
@return true if an edge was selected
Ghidra/Features/GraphServices/src/main/java/ghidra/graph/visualization/mouse/AbstractJgtGraphMousePlugin.java