code: public static long distance(String A, String B)
      {
          CommonSynonymDictionary.SynonymItem itemA = get(A);
          CommonSynonymDictionary.SynonymItem itemB = get(B);
          if (itemA == null || itemB == null) return Long.MAX_VALUE;
  
          return distance(itemA, itemB);
      }
docs: 判断两个单词之间的语义距离
  @param A
  @param B
  @return