<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def find_replacement(self):
 """ Finds a replacement for the current node The replacement is returned as a (replacement-node, replacements-parent-node) tuple """


        if self.right:
            child, parent = self.right.extreme_child(min, self.axis)
        else:
            child, parent = self.left.extreme_child(max, self.axis)

        return (child, parent if parent is not None else self)