internal override string Extract(History h, PairsHolder pH)
        {
            StringBuilder sb = new StringBuilder();

            for (int j = left; j <= right; j++)
            {
                string word    = pH.GetWord(h, j);
                string distSim = lexicon.GetMapping(word);
                sb.Append(distSim);
                if (j < right)
                {
                    sb.Append('|');
                }
            }
            return(sb.ToString());
        }
        internal override string Extract(History h, PairsHolder pH)
        {
            string word = base.Extract(h, pH);

            return(lexicon.GetMapping(word));
        }