<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def box_coordinates(self):
 """Returns a thumbnail's coordinates."""

        if (
            self.thumb_x is not None and
            self.thumb_y is not None and
            self.thumb_x2 is not None and
            self.thumb_y2 is not None
        ):
            return (
                int(self.thumb_x),
                int(self.thumb_y),
                int(self.thumb_x2),
                int(self.thumb_y2),
            )
        return False