code: def extract(self, m):
          
          self._clear()
          self.m = m
          # self._preprocess()
  
          if self.option != []:
              self._url_filter()
              self._email_filter()
              if 'tex' in self.option:
                  self._tex_filter()
              # if 'email' in self.option:
              #     self._email_filter()
              if 'telephone' in self.option:
                  self._telephone_filter()
              if 'QQ' in self.option:
                  self._QQ_filter()
              if 'emoji' in self.option:
                  self._emoji_filter()
              if 'wechat' in self.option:
                  self._wechat_filter()
          self._filter()
          if 'blur' in self.option:
              self._blur = get_number(self.m, self._limit)
  
          return self._get_result()
docs: extract info specified in option