code: def recognise(self):
          
          result = ""
          for side in "LFRB":
              for square in self.cube.get_face(side)[0]:
                  for _side in "LFRB":
                      if square.colour == self.cube[_side].colour:
                          result += _side
                          break
          return result
docs: Recognise the PLL case of Cube.