code: def heading(cls, heading_text, char='=', level=0, ansi=False):
          
          heading_color = cls.headings[level] if ansi else '%s'
          if char is None:
              return heading_color % '%s\n' % heading_text
          else:
              heading_ul = char*len(heading_text)
              return heading_color % '%s\n%s\n%s' % (heading_ul, heading_text, heading_ul)
docs: Turn the supplied heading text into a suitable heading with
          optional underline and color.