'Volume extend completes successfully.'

def test_extend_lun(self):

    new_volume_size = 10
    change_in_size_mb = ((new_volume_size - VOLUME['size']) * units.Ki)
    response = {'success': True, 'message': 'Expand    resource    successfully'}
    conf = {'lun.extend_lun.return_value': response}
    self.driver.vmem_mg = self.setup_mock_concerto(m_conf=conf)
    self.driver._send_cmd = mock.Mock(return_value=response)
    result = self.driver._extend_lun(VOLUME, new_volume_size)
    self.driver._send_cmd.assert_called_with(self.driver.vmem_mg.lun.extend_lun, response['message'], VOLUME['id'], change_in_size_mb)
    self.assertIsNone(result)
