text: """Tests for dict_util."""
  
  import dict_util
  import unittest
  
  
  class DictUtilTest(unittest.TestCase):
  
    def test_deep_get(self):
      c = {'c': 1}
      b = {'b': c}
      a = {'a': b}
      self.assertEqual(dict_util.deep_get(a, 'a'), b)
      self.assertEqual(dict_util.deep_get(a, 'a', 'b'), c)
      self.assertEqual(dict_util.deep_get(a, 'a', 'b', 'c'), 1)
      self.assertEqual(dict_util.deep_get(a, 'b'), None)
      self.assertEqual(dict_util.deep_get(a, 'a', 'c'), None)
      self.assertEqual(dict_util.deep_get(a, 'a', 'b', 'd'), None)
  