text: #
  # Copyright 2017 Google Inc.
  #
  # 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 unittest2
  import datetime
  from google.cloud import datastore
  from common import image_sorter
  from common import config
  import time
  
  class ImageSorterTest(unittest2.TestCase):
      """
      Tests for image_sorter code.
      """
  
      def test_sort_newest(self):
          datastore_client = datastore.Client(config.PROJECT_ID)
          key = datastore_client.key('Photo', '1')
          entity = datastore.Entity(key=key)
          entity["image_datetime"] = datetime.datetime.utcnow()
          time.sleep(1)
          key = datastore_client.key('Photo', '2')
          entity2 = datastore.Entity(key=key)
          entity2["image_datetime"] = datetime.datetime.utcnow()
          time.sleep(1)
          key = datastore_client.key('Photo', '3')
          entity3 = datastore.Entity(key=key)
          entity3["image_datetime"] = datetime.datetime.utcnow()
  
          entities = [entity, entity2, entity3]
          self.assertEqual(image_sorter.pick_image(entities), entity3)
          entities = [entity3, entity2, entity]
          self.assertEqual(image_sorter.pick_image(entities), entity3)
          entities = [entity2, entity3, entity]
          self.assertEqual(image_sorter.pick_image(entities), entity3)
  