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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 set_midplane(self, midplane):
 """ Sets the midplane model. :returns: midplane model string (e.g. "vxr" or "std") """


        yield from self._hypervisor.send('c7200 set_midplane "{name}" {midplane}'.format(name=self._name, midplane=midplane))

        log.info('Router "{name}" [{id}]: midplane updated from {old_midplane} to {new_midplane}'.format(name=self._name,
                                                                                                         id=self._id,
                                                                                                         old_midplane=self._midplane,
                                                                                                         new_midplane=midplane))
        self._midplane = midplane