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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 move_after(self, node_id):
 """ Moving one node of tree after another For example see :mod:`sqlalchemy_mptt.tests.cases.move_node.test_move_after_function` """
  # noqa
        session = Session.object_session(self)
        self.parent_id = self.parent_id
        self.mptt_move_after = node_id
        session.add(self)