              if accessor_name in self.opts.fields:
                  if self.opts.depth:
                      ret[accessor_name] = self.get_nested_field(*relation_info)
                  else:
                      ret[accessor_name] = self.get_related_field(*relation_info)
  
          return ret
  
      def get_url_field(self):
          return None
 
</s> remove                     ret[accessor_name] = self.get_nested_field(*relation_info)
 </s> add                     ret[accessor_name] = self.get_nested_field(accessor_name, *relation_info) </s> remove                 ret[field_name] = self.get_related_field(*relation_info)
 </s> add                 ret[field_name] = self.get_related_field(field_name, *relation_info) </s> remove                 ret[field_name] = self.get_nested_field(*relation_info)
 </s> add                 ret[field_name] = self.get_nested_field(field_name, *relation_info) </s> remove     def get_pk_field(self, model_field):
 </s> add     def get_pk_field(self, field_name, model_field): </s> remove     def get_pk_field(self, model_field):
 </s> add     def get_pk_field(self, field_name, model_field):
                    ret[accessor_name] = self.get_related_field(accessor_name, *relation_info)
              if accessor_name in self.opts.fields:
                  if self.opts.depth:
                      ret[accessor_name] = self.get_nested_field(*relation_info)
                  else:
                    ret[accessor_name] = self.get_related_field(accessor_name, *relation_info)
  
          return ret
  
      def get_url_field(self):
          return None
keep keep keep keep replace keep keep keep keep keep
 Drop label from serializer fields when not needed 
rest_framework/serializers.py