public void testGetOriginalEdgeInstance()
        {
            IList <Edge> originalEdges = new List <Edge> {
                edgeX1, edgeY1
            };

            EdgeMapper <Edge, Vertex, Weight> edgeMapper = EdgeMapper <Edge, Vertex, Weight> .CreateEdgeMapper <Edge, Vertex, Weight>(originalEdges);

            // the same edge instance should be retrieve when we below pass in the string ids for the vertices of the edge

            AreSame(edgeX1, edgeMapper.GetOriginalEdgeInstance(edgeX1.StartVertex.VertexId, edgeX1.EndVertex.VertexId));
            AreSame(edgeY1, edgeMapper.GetOriginalEdgeInstance(edgeY1.StartVertex.VertexId, edgeY1.EndVertex.VertexId));
        }
 protected E GetOriginalEdgeInstance(string startVertexId, string endVertexId)
 {
     return(edgeMapper.GetOriginalEdgeInstance(startVertexId, endVertexId));
 }