default_value.DebugString())
                .data());
      }
    } break;
    case tensorflow::AttrValue::kTensor:
      TF_FALLTHROUGH_INTENDED;
    case tensorflow::AttrValue::kPlaceholder:
      TF_FALLTHROUGH_INTENDED;
    case tensorflow::AttrValue::VALUE_NOT_SET:
      TF_SetStatus(
          status, TF_UNIMPLEMENTED,