public override bool Equals(object obj)
        {
            Segment objSegment = (Segment)obj;

            if (LeftVertex.Equals(objSegment.LeftVertex) && RightVertex.Equals(objSegment.RightVertex))
            {
                return(true);
            }
            return(false);
        }
 public override string ToString()
 {
     return(LeftVertex.ToString() + " --> " + RightVertex.ToString());
 }