<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def is_solved(self):
 """ Check if Cube is solved. """

        for side in "LUFDRB":
            sample = self.cube[side].facings[side]
            for square in sum(self.cube.get_face(side), []):
                if square != sample:
                    return False
        return True