code: def remove_enclosure(self, left_char, right_char):
          
          assert len(left_char) == 1, \
              "Parameter left_char must be character not string"
          assert len(right_char) == 1, \
              "Parameter right_char must be character not string"
          rm_enclosure = (left_char, right_char)
          if rm_enclosure in self._enclosure:
              self._enclosure.remove(rm_enclosure)
  
          self._after_tld_chars = self._get_after_tld_chars()
docs: Remove enclosure pair from set of enclosures.
  
          :param str left_char: left character of enclosure pair - e.g. "("
          :param str right_char: right character of enclosure pair - e.g. ")"