}         // GetHashCode

        // ----------------------------------------------------------------------
        protected virtual int ComputeHashCode()
        {
            return(HashTool.ComputeHashCode(this));
        } // ComputeHashCode
        }         // HasSameData

        // ----------------------------------------------------------------------
        protected override int ComputeHashCode()
        {
            return(HashTool.ComputeHashCode(base.ComputeHashCode(), direction));
        }         // ComputeHashCode