          'invalid': _('Value must be valid JSON.')
      }
  
      def __init__(self, *args, **kwargs):
          self.binary = kwargs.pop('binary', False)
          self.encoder = kwargs.pop('encoder', None)
          self.decoder = kwargs.pop('decoder', None)
          super().__init__(*args, **kwargs)
 
</s> remove                 value = json.dumps(self.value, sort_keys=True, indent=4)
 </s> add                 value = json.dumps(
                    self.value,
                    sort_keys=True,
                    indent=4,
                    separators=(',', ': '),
                ) </s> remove         serializer = ExampleSerializer(data={'nested': {'bool_field': False, 'null_field': None}})
 </s> add         serializer = ExampleSerializer(
            data={'nested': {
                'bool_field': False, 'null_field': None,
                'json_field': {'bool_item': True, 'number': 1, 'text_item': 'text'},
                'custom_json_field': {'bool_item': True, 'number': 1, 'text_item': 'text'},
            }})
    # Workaround for isinstance calls when importing the field isn't possible
    _is_jsonfield = True

          'invalid': _('Value must be valid JSON.')
      }
  
    # Workaround for isinstance calls when importing the field isn't possible
    _is_jsonfield = True

      def __init__(self, *args, **kwargs):
          self.binary = kwargs.pop('binary', False)
          self.encoder = kwargs.pop('encoder', None)
          self.decoder = kwargs.pop('decoder', None)
          super().__init__(*args, **kwargs)
keep keep add keep keep keep keep keep
 Render JSON fields with proper indentation in browsable API forms. (#6243)

* Fix JSONBoundField usage on nested serializers (#6211)

* Unify JSONBoundField as_form_field output between py2 and py3

When using json.dumps with indenting, in python2 the default formatting
prints whitespace after commas (,) and python3 does not. This can be
unified with the separators keyword argument. 
rest_framework/fields.py