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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def remove(self):
 """ Remove the node from the tree. Returns the position of the node in its parent's children before it was removed. """

        if self.parent:
            for i, node in enumerate(self.parent.children):
                if node is self:
                    self.parent.changed()
                    del self.parent.children[i]
                    self.parent = None
                    return i