/**
         * {@inheritDoc}
         */
        public override E removeEdge(V sourceVertex, V targetVertex)
        {
            E e = getEdge(sourceVertex, targetVertex);

            if (e != null)
            {
                specifics.removeEdgeFromTouchingVertices(e);
                intrusiveEdgesSpecifics.remove(e);
            }

            return(e);
        }