code: public static CoreDictionary.Attribute guessAttribute(Term term)
      {
          CoreDictionary.Attribute attribute = CoreDictionary.get(term.word);
          if (attribute == null)
          {
              attribute = CustomDictionary.get(term.word);
          }
          if (attribute == null)
          {
              if (term.nature != null)
              {
                  if (Nature.nx == term.nature)
                      attribute = new CoreDictionary.Attribute(Nature.nx);
                  else if (Nature.m == term.nature)
                      attribute = CoreDictionary.get(CoreDictionary.M_WORD_ID);
              }
              else if (term.word.trim().length() == 0)
                  attribute = new CoreDictionary.Attribute(Nature.x);
              else attribute = new CoreDictionary.Attribute(Nature.nz);
          }
          else term.nature = attribute.nature[0];
          return attribute;
      }
docs: 查询或猜测一个词语的属性，
  先查词典，然后对字母、数字串的属性进行判断，最后猜测未登录词
  @param term
  @return