<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def move_red_left(self):
 """ Shuffle red to the left of a tree. """


        self = self.flip()
        if self.right is not NULL and self.right.left.red:
            self = self._replace(right=self.right.rotate_right())
            self = self.rotate_left().flip()

        return self