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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 common_parent(self, node):
 """ Return the common parent of two entities If the entities have no common parent, return None. Parameters node : instance of Node The other node. Returns ------- parent : instance of Node | None The parent. """

        p1 = self.parent_chain()
        p2 = node.parent_chain()
        for p in p1:
            if p in p2:
                return p
        return None