<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def middle(self):
 """ Returns the middle point of the bounding box :return: middle point :rtype: (float, float) """

        return (self.min_x + self.max_x) / 2, (self.min_y + self.max_y) / 2