new_contents: # Copyright 2014 IBM Corp.
  #
  #    Licensed under the Apache License, Version 2.0 (the "License"); you may
  #    not use this file except in compliance with the License. You may obtain
  #    a copy of the License at
  #
  #         http://www.apache.org/licenses/LICENSE-2.0
  #
  #    Unless required by applicable law or agreed to in writing, software
  #    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  #    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  #    License for the specific language governing permissions and limitations
  #    under the License.
  
  import time
  
  import mock
  
  from tempest.common import waiters
  from tempest import exceptions
  from tempest.tests import base
  
  
  class TestImageWaiters(base.TestCase):
      def setUp(self):
          super(TestImageWaiters, self).setUp()
          self.client = mock.MagicMock()
          self.client.build_timeout = 1
          self.client.build_interval = 1
  
      def test_wait_for_image_status(self):
          self.client.get_image.return_value = (None, {'status': 'active'})
          start_time = int(time.time())
          waiters.wait_for_image_status(self.client, 'fake_image_id', 'active')
          end_time = int(time.time())
          # Ensure waiter returns before build_timeout
          self.assertTrue((end_time - start_time) < 10)
  
      def test_wait_for_image_status_timeout(self):
          self.client.get_image.return_value = (None, {'status': 'saving'})
          self.assertRaises(exceptions.TimeoutException,
                            waiters.wait_for_image_status,
                            self.client, 'fake_image_id', 'active')
  
      def test_wait_for_image_status_error_on_image_create(self):
          self.client.get_image.return_value = (None, {'status': 'ERROR'})
          self.assertRaises(exceptions.AddImageException,
                            waiters.wait_for_image_status,
                            self.client, 'fake_image_id', 'active')
  
subject: Add unit tests for image waiter