new_contents: # Copyright 2014 NEC Corporation.
  # All Rights Reserved.
  #
  #    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.
  
  
  from tempest.common.utils import misc
  from tempest.tests import base
  
  
  @misc.singleton
  class TestFoo(object):
  
      count = 0
  
      def increment(self):
          self.count += 1
          return self.count
  
  
  @misc.singleton
  class TestBar(object):
  
      count = 0
  
      def increment(self):
          self.count += 1
          return self.count
  
  
  class TestMisc(base.TestCase):
  
      def test_singleton(self):
          test = TestFoo()
          self.assertEqual(0, test.count)
          self.assertEqual(1, test.increment())
          test2 = TestFoo()
          self.assertEqual(1, test.count)
          self.assertEqual(1, test2.count)
          self.assertEqual(test, test2)
          test3 = TestBar()
          self.assertNotEqual(test, test3)
  
subject: Add utils.misc unit tests