/// <summary>
 /// Sets a <see cref="IItemFactory.SetTemporaryPortConstraint">temporary west port constraint</see>
 /// on <paramref name="source"/> or target side of <paramref name="edge"/>
 /// </summary>
 private static void ConstrainWest(Edge edge, bool source, IItemFactory itemFactory)
 {
     itemFactory.SetTemporaryPortConstraint(edge, source, portConstraintWest);
 }