  
          if fields:
              return model_fields & set(as_tuple(fields))
  
          return model_fields - set(as_tuple(exclude_fields))
      
      @property
      def _property_fields_set(self):
          """Returns a set containing the names of validated properties on the model."""
          resource = self.view.resource
 
</s> remove         """Returns a set containing the names of validated properties on the model."""
        resource = self.view.resource
        model = getattr(resource, 'model', None)
        fields = getattr(resource, 'fields', self.fields)
        exclude_fields = getattr(resource, 'exclude_fields', self.exclude_fields)

        property_fields = set(attr for attr in dir(model) if
                              isinstance(getattr(model, attr, None), property)
 </s> add         """
        Returns a set containing the names of validated properties on the model.
        """
        property_fields = set(attr for attr in dir(self.model) if
                              isinstance(getattr(self.model, attr, None), property) </s> remove         return property_fields - set(as_tuple(exclude_fields))
 </s> add         return property_fields - set(as_tuple(self.exclude)) </s> remove             return property_fields & set(as_tuple(fields))
 </s> add             return property_fields & set(as_tuple(self.fields)) </s> remove     def _get_content(self):
 </s> add     def validate_request(self, data, files):
        """
        Given the request data return the cleaned, validated content.
        Typically raises a ErrorResponse with status code 400 (Bad Request) on failure.
        """
        return model_fields - set(as_tuple(self.exclude))
  
          if fields:
              return model_fields & set(as_tuple(fields))
  
        return model_fields - set(as_tuple(self.exclude))
      
      @property
      def _property_fields_set(self):
          """Returns a set containing the names of validated properties on the model."""
          resource = self.view.resource
keep keep keep keep replace keep keep keep keep keep
 Sorting out resources.  Doing some crazy magic automatic url resolving stuff.  Yum. 
djangorestframework/resources.py