  RENDERER_B_SERIALIZER = lambda x: ('Renderer B: %s' % x).encode('ascii')
  
  
  expected_results = [
      ((elem for elem in [1, 2, 3]), JSONRenderer, '[1, 2, 3]')  # Generator
  ]
  
  
  class BasicRendererTests(TestCase):
      def test_expected_results(self):
 
</s> remove     Renderer which serializes to json.
 </s> add     Renderer which serializes to JSON.
    Applies JSON's backslash-u character escaping for non-ascii characters. </s> remove         Render `obj` into json.
 </s> add         Render `data` into JSON. </s> remove     charset = 'iso-8859-1'
 </s> add     charset = 'utf-8'
    # Note that JSON encodings must be utf-8, utf-16 or utf-32.
    # See: http://www.ietf.org/rfc/rfc4627.txt </s> remove         return "%s(%s);" % (callback, json)
 </s> add         return callback.encode(self.charset) + b'(' + json + b');'
    ((elem for elem in [1, 2, 3]), JSONRenderer, b'[1, 2, 3]')  # Generator
  RENDERER_B_SERIALIZER = lambda x: ('Renderer B: %s' % x).encode('ascii')
  
  
  expected_results = [
    ((elem for elem in [1, 2, 3]), JSONRenderer, b'[1, 2, 3]')  # Generator
  ]
  
  
  class BasicRendererTests(TestCase):
      def test_expected_results(self):
keep keep keep keep replace keep keep keep keep keep
 Last bits of charset sorting-out-ness 
rest_framework/tests/renderers.py