const void* const* values, const size_t* lengths,
                          int num_values) {
  if (strcmp(attr_name, tensorflow::kColocationAttrName) == 0) {
    desc->colocation_constraints.clear();
    for (int i = 0; i < num_values; ++i) {
      desc->colocation_constraints.emplace(static_cast<const char*>(values[i]),
                                           lengths[i]);
    }
  } else {