public IEdge CreateEdge(INode iSource, INode iTarget, EdgeData iData = null) { if (iSource == null || iTarget == null) { return(null); } var tNewEdge = mCreator.CreateEdge(m_nextEdgeId.ToString(), iSource, iTarget, iData); m_nextEdgeId++; AddEdge(tNewEdge); return(tNewEdge); }