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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 prune_unrepresented(self):
 """ Remove nodes without sequences or children below this node. """

        for node in self.depth_first_iter(self_first=False):
            if (not node.children and
                    not node.sequence_ids and
                    node is not self):
                node.parent.remove_child(node)