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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 add_gre_port(self, name, remote_ip, local_ip=None, key=None, ofport=None):
 """ Creates a GRE tunnel port. See the description of ``add_tunnel_port()``. """

        self.add_tunnel_port(name, 'gre', remote_ip,
                             local_ip=local_ip, key=key, ofport=ofport)