code: def max_height(self):
          
          if len(self._plain_images) <= 0:
              self._convert_images()
  
          if self._max_height == 0:
              for image in self._plain_images:
                  self._max_height = max(len(image), self._max_height)
          return self._max_height
docs: :return: The max height of the rendered text (across all images if an
              animated renderer).