'If dictsort is passed something other than a list of dictionaries,
fail silently.'

def test_invalid_values(self):

    self.assertEqual(dictsort([1, 2, 3], 'age'), '')
    self.assertEqual(dictsort('Hello!', 'age'), '')
    self.assertEqual(dictsort({'a': 1}, 'age'), '')
    self.assertEqual(dictsort(1, 'age'), '')
