code: def _le_butt(self, annot, p1, p2, lr):
          
          m, im, L, R, w, scol, fcol, opacity = self._le_annot_parms(annot, p1, p2)
          shift = 3
          d = shift * max(1, w)
          M = R if lr else L
          top = (M + (0, -d/2.)) * im
          bot = (M + (0, d/2.)) * im
          ap = "\nq\n%s%f %f m\n" % (opacity, top.x, top.y)
          ap += "%f %f l\n" % (bot.x, bot.y)
          ap += "%g w\n" % w
          ap += scol + "s\nQ\n"
          return ap
docs: Make stream commands for butt line end symbol. "lr" denotes left (False) or right point.