          # Since both templates and all four contexts represent the same thing,
          # they all render the same (and are returned as unicode objects and
          # "safe" objects as well, for auto-escaping purposes).
          self.assertEqual(t1.render(c3), t2.render(c3))
          self.assertIsInstance(t1.render(c3), six.text_type)
          self.assertIsInstance(t1.render(c3), SafeData)
 
</s> remove         if isinstance(ds_input, six.string_types) and json_regex.match(ds_input):
 </s> add         if isinstance(ds_input, str) and json_regex.match(ds_input): </s> remove 

def to_unicode(s):
    """
    Convert strings to Unicode objects (and return all other data types
    unchanged).
    """
    if isinstance(s, six.string_types):
        return force_text(s)
    return s
 </s> add  </s> remove                 if isinstance(field_value, six.string_types):
 </s> add                 if isinstance(field_value, str): </s> remove         # Empty strings should be returned as Unicode
 </s> add         # Empty strings should be returned as string </s> remove             six.text_type(f),
 </s> add             str(f),
        self.assertIsInstance(t1.render(c3), str)
          # Since both templates and all four contexts represent the same thing,
          # they all render the same (and are returned as unicode objects and
          # "safe" objects as well, for auto-escaping purposes).
          self.assertEqual(t1.render(c3), t2.render(c3))
        self.assertIsInstance(t1.render(c3), str)
          self.assertIsInstance(t1.render(c3), SafeData)
keep keep keep keep replace keep
 Refs #23919 -- Removed six.<various>_types usage

Thanks Tim Graham and Simon Charette for the reviews. 
tests/template_tests/test_unicode.py