// `value` must point to a string of length `length` bytes.
TF_CAPI_EXPORT extern void TF_SetAttrString(TF_OperationDescription* desc,
                                            const char* attr_name,
                                            const void* value, size_t length);
// `values` and `lengths` each must have lengths `num_values`.
// `values[i]` must point to a string of length `lengths[i]` bytes.