/**
* If there is an edge equal to e already in the list, return it. Otherwise return null.
*
* @return equal edge, if there is one already in the list null otherwise
*/
public Edge findEqualEdge(final Edge e) {
final OrientedCoordinateArray oca = new OrientedCoordinateArray(e.getLine());
// will return null if no edge matches
final Edge matchEdge = this.ocaMap.get(oca);
return matchEdge;
}
/** Insert an edge unless it is already in the list */
public void add(final Edge edge) {
this.edges.add(edge);
final OrientedCoordinateArray oca = new OrientedCoordinateArray(edge.getLine());
this.ocaMap.put(oca, edge);
}