  
          # Cast everything to strings for ease.
          for key, val in value.items():
              if val is not None:
                  val = six.text_type(val)
              value[key] = val
          return value
  
      def has_changed(self, initial, data):
          """
 
</s> remove             if not isinstance(val, six.string_types) and val is not None:
 </s> add             if not isinstance(val, str) and val is not None: </s> remove             u_params = tuple(to_unicode(val) for val in params)
 </s> add             u_params = tuple(to_string(val) for val in params) </s> remove get_format_lazy = lazy(get_format, six.text_type, list, tuple)
 </s> add get_format_lazy = lazy(get_format, str, list, tuple) </s> remove         if isinstance(value, six.string_types):
 </s> add         if isinstance(value, str): </s> remove             u_params = {to_unicode(k): to_unicode(v) for k, v in params.items()}
 </s> add             u_params = {to_string(k): to_string(v) for k, v in params.items()}
                val = str(val)
  
          # Cast everything to strings for ease.
          for key, val in value.items():
              if val is not None:
                val = str(val)
              value[key] = val
          return value
  
      def has_changed(self, initial, data):
          """
keep keep keep keep replace keep keep keep keep keep
 Refs #23919 -- Removed six.<various>_types usage

Thanks Tim Graham and Simon Charette for the reviews. 
django/contrib/postgres/forms/hstore.py