          'required': 'This field is required.',
          'blank': 'This field may not be blank.'
      }
  
      def __init__(self, *args, **kwargs):
          self.allow_blank = kwargs.pop('allow_blank', False)
          super(CharField, self).__init__(*args, **kwargs)
  
      def to_native(self, data):
          if data == '' and not self.allow_blank:
 
</s> remove         super(CharField, self).__init__(*args, **kwargs)
 </s> add         self.max_length = kwargs.pop('max_length', None)
        self.min_length = kwargs.pop('min_length', None)
        super(CharField, self).__init__(**kwargs) </s> remove     def __init__(self, *args, **kwargs):
 </s> add     def __init__(self, **kwargs): </s> remove         super(ChoiceField, self).__init__(*args, **kwargs)
 </s> add         super(ChoiceField, self).__init__(**kwargs) </s> remove             # if model_field.help_text is not None:
            #     kwargs['help_text'] = model_field.help_text
 </s> add             #  if model_field.help_text is not None:
            #      kwargs['help_text'] = model_field.help_text </s> remove                 files = request.FILES
 </s> add                 # files = request.FILES
    def __init__(self, **kwargs):
          'required': 'This field is required.',
          'blank': 'This field may not be blank.'
      }
  
    def __init__(self, **kwargs):
          self.allow_blank = kwargs.pop('allow_blank', False)
          super(CharField, self).__init__(*args, **kwargs)
  
      def to_native(self, data):
          if data == '' and not self.allow_blank:
keep keep keep keep replace keep keep keep keep keep
 Add relations and get tests running 
rest_framework/fields.py