docs: def _get_text(self, text):
          """Returns the text content of `text`, with all multi-character tokens
          replaced with a single character. Substitutions are recorded
          in self._substitutes.
  
          :param text: text to get content from
          :type text: `Text`
          :rtype: `str`
  
          """
          tokens = text.get_tokens()
          for i, token in enumerate(tokens):
              if len(token) > 1:
                  char = chr(self._char_code)
                  substitute = self._substitutes.setdefault(token, char)
                  if substitute == char:
                      self._char_code += 1
                  tokens[i] = substitute
          return self._tokenizer.joiner.join(tokens)