code: def polyline(self, vertexes, attr=0, row=None):
          'adds lines for (x,y) vertexes of a polygon'
          self.polylines.append((vertexes, attr, row)f polyline(self, vertexes, attr=0, row=None):
          'adds lines for (x,y) vertexes of a polygon'
          self.polylines.append((vertexes, attr, row))
docs: adds lines for (x,y) vertexes of a polygon