code: def _render_line(self, line, settings):
          
          s = self._es(settings, self.SETTING_WIDTH, self.SETTING_FLAG_BORDER, self.SETTING_MARGIN, self.SETTING_MARGIN_LEFT, self.SETTING_MARGIN_RIGHT)
          width_content = self.calculate_width_widget_int(**s)
  
          s = self._es_content(settings)
          s[self.SETTING_WIDTH] = width_content
          line = self.fmt_content(line, **s)
  
          s = self._es_text(settings, settings[self.SETTING_TEXT_FORMATING])
          line = self.fmt_text(line, **s)
  
          s = self._es(settings, self.SETTING_BORDER_STYLE)
          bchar = self.bchar('v', 'm', **s)
  
          s = self._es_text(settings, settings[self.SETTING_BORDER_FORMATING])
          bchar = self.fmt_text(bchar, **s)
  
          line = '{}{}{}'.format(bchar, line, bchar)
          s = self._es_margin(settings)
          line = self.fmt_margin(line, **s)
          return line
docs: Render single box line.