          field_cls = self.serializer_related_class
          kwargs = get_relation_kwargs(field_name, relation_info)
  
          # `view_name` is only valid for hyperlinked relationships.
          if not issubclass(field_cls, HyperlinkedRelatedField):
              kwargs.pop('view_name', None)
  
          return field_cls, kwargs
  
      def build_nested_field(self, field_name, info, model, nested_depth):
          """
 
</s> remove         relation_info = info.relations[field_name]

        field_cls = self.serializer_related_class
        kwargs = get_relation_kwargs(field_name, relation_info)
 </s> add         field_class = self.serializer_related_class
        field_kwargs = get_relation_kwargs(field_name, relation_info) </s> remove         return field_cls, kwargs
 </s> add         return field_class, field_kwargs </s> remove     def build_nested_field(self, field_name, info, model, nested_depth):
 </s> add     def build_nested_field(self, field_name, relation_info, nested_depth): </s> remove         relation_info = info.relations[field_name]

 </s> add  </s> remove         return field_cls, kwargs
 </s> add         return field_class, field_kwargs
        if not issubclass(field_class, HyperlinkedRelatedField):
            field_kwargs.pop('view_name', None)
          field_cls = self.serializer_related_class
          kwargs = get_relation_kwargs(field_name, relation_info)
  
          # `view_name` is only valid for hyperlinked relationships.
        if not issubclass(field_class, HyperlinkedRelatedField):
            field_kwargs.pop('view_name', None)
        if not issubclass(field_class, HyperlinkedRelatedField):
            field_kwargs.pop('view_name', None)
  
          return field_cls, kwargs
  
      def build_nested_field(self, field_name, info, model, nested_depth):
          """
keep keep keep keep replace replace keep keep keep keep keep
 Final bits of docs for ModelSerializer fields API 
rest_framework/serializers.py