code: def img(self):
          '''return a cv image for the thumbnail'''
          if self._img is not None:
              return self._img 
          self._img = cv2.cvtColor(self.original_img, cv2.COLOR_BGR2RGB)
          if self.border_width and self.border_colour is not None:
              cv2.rectangle(self._img, (0, 0), (self.width-1, self.height-1),
                            self.border_colour, self.border_width)
          return self._imf img(self):
          '''return a cv image for the thumbnail'''
          if self._img is not None:
              return self._img 
          self._img = cv2.cvtColor(self.original_img, cv2.COLOR_BGR2RGB)
          if self.border_width and self.border_colour is not None:
              cv2.rectangle(self._img, (0, 0), (self.width-1, self.height-1),
                            self.border_colour, self.border_width)
          return self._img
docs: return a cv image for the thumbnail