code: def set_ram(self, ram):
          
  
          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
docs: Sets amount of RAM allocated to this router
  
          :param ram: amount of RAM in Mbytes (integer)