docs: def _render_internal_label(self):
          ''' Render with a label inside the bar graph. '''
          ncc = self._num_complete_chars
          bar = self._lbl.center(self.iwidth)
          cm_chars = self._comp_style(bar[:ncc])
          em_chars = self._empt_style(bar[ncc:])
          return f'{self._first}{cm_chars}{em_chars}{self._last}'