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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 assert_is_known_node_id(self, node_list_pyxb, node_id):
 """When importing from a CN, ensure that the NodeID which the ObjectList will be filtered by is known to the CN."""

        node_pyxb = self.find_node_by_id(node_list_pyxb, node_id)
        assert node_pyxb is not None, (
            "The NodeID of this GMN instance is unknown to the CN at the provided BaseURL. "
            'node_id="{}" base_url="{}"'.format(node_id, self.options["baseurl"])
        )