      def set_context(self, serializer):
          # Determine the existing instance, if this is an update operation.
          self.instance = getattr(serializer, 'instance', None)
  
          # Ensure uniqueness.
          filter_kwargs = dict([
              (field_name, attrs[field_name]) for field_name in self.fields
          ])
 
</s> remove         instance = getattr(serializer, 'instance', None)
 </s> add         self.instance = getattr(serializer, 'instance', None) </s> remove     def __call__(self, value):
        serializer = self.serializer_field

 </s> add     def set_context(self, serializer): </s> remove             (field_name, value[field_name]) for field_name in self.fields
 </s> add             (field_name, attrs[field_name]) for field_name in self.fields </s> remove         instance = getattr(field.parent, 'instance', None)
 </s> add         self.instance = getattr(serializer_field.parent, 'instance', None)
    def __call__(self, attrs):
      def set_context(self, serializer):
          # Determine the existing instance, if this is an update operation.
          self.instance = getattr(serializer, 'instance', None)
  
    def __call__(self, attrs):
          # Ensure uniqueness.
          filter_kwargs = dict([
              (field_name, attrs[field_name]) for field_name in self.fields
          ])
keep keep keep add keep keep keep keep
 First pass at unique_for_date, unique_for_month, unique_for_year 
rest_framework/validators.py