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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_ram(self, ram):
 """ Sets amount of RAM allocated to this router :param ram: amount of RAM in Mbytes (integer) """


        if self._ram == ram:
            return

        yield from self._hypervisor.send('vm set_ram "{name}" {ram}'.format(name=self._name, ram=ram))
        log.info('Router "{name}" [{id}]: RAM updated from {old_ram}MB to {new_ram}MB'.format(name=self._name,
                                                                                              id=self._id,
                                                                                              old_ram=self._ram,
                                                                                              new_ram=ram))
        self._ram = ram