'Extend a VMAX volume.
:param array: the array serial number
:param device_id: volume device id
:param new_size: the new required size for the device
:param extra_specs: the extra specifications'

def extend_volume(self, array, device_id, new_size, extra_specs):

    extend_vol_payload = {'executionOption': 'ASYNCHRONOUS', 'editVolumeActionParam': {'expandVolumeParam': {'volumeAttribute': {'volume_size': new_size, 'capacityUnit': 'GB'}}}}
    (status_code, job) = self._modify_volume(array, device_id, extend_vol_payload)
    LOG.debug('Extend    Device:    %(device_id)s.    Status    code:    %(sc)lu.', {'device_id': device_id, 'sc': status_code})
    self.wait_for_job('Extending    volume', status_code, job, extra_specs)
