code: def stroke_linecap(self, linecap):
          
          linecap = getattr(pgmagick.LineCap, "%sCap" % linecap.title())
          linecap = pgmagick.DrawableStrokeLineCap(linecap)
          self.drawer.append(linecap)
docs: set to stroke linecap.
  
          :param linecap: 'undefined', 'butt', 'round', 'square'
          :type linecap: str