Set I/O memory size for this router.

        :param iomem: I/O memory size

def set_iomem(self, iomem):
        """
        Set I/O memory size for this router.

        :param iomem: I/O memory size
        """

        yield from self._hypervisor.send('c3600 set_iomem "{name}" {size}'.format(name=self._name, size=iomem))

        log.info('Router "{name}" [{id}]: I/O memory updated from {old_iomem}% to {new_iomem}%'.format(name=self._name,
                                                                                                       id=self._id,
                                                                                                       old_iomem=self._iomem,
                                                                                                       new_iomem=iomem))
        self._iomem = iomem