code: def draw(self, img, pixmapper, bounds):
          '''draw the trail'''
          for p in self.points:
              (px,py) = pixmapper(p)
              (width, height) = image_shape(img)
              if px >= 0 and py >= 0 and px < width and py < height:
                  cv2.circle(img, (px,py), 1, self.colourf draw(self, img, pixmapper, bounds):
          '''draw the trail'''
          for p in self.points:
              (px,py) = pixmapper(p)
              (width, height) = image_shape(img)
              if px >= 0 and py >= 0 and px < width and py < height:
                  cv2.circle(img, (px,py), 1, self.colour)
docs: draw the trail