      }
  
      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:
              self.fail('blank')
          return str(data)
 
</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     def __init__(self, *args, **kwargs):
 </s> add     def __init__(self, **kwargs): </s> remove                 files = request.FILES
 </s> add                 # files = request.FILES </s> remove             files = None
 </s> add             # files = None
        self.max_length = kwargs.pop('max_length', None)
        self.min_length = kwargs.pop('min_length', None)
        super(CharField, self).__init__(**kwargs)
      }
  
      def __init__(self, *args, **kwargs):
          self.allow_blank = kwargs.pop('allow_blank', False)
        self.max_length = kwargs.pop('max_length', None)
        self.min_length = kwargs.pop('min_length', None)
        super(CharField, self).__init__(**kwargs)
  
      def to_native(self, data):
          if data == '' and not self.allow_blank:
              self.fail('blank')
          return str(data)
keep keep keep keep replace keep keep keep keep keep
 Add relations and get tests running 
rest_framework/fields.py