memcpy(&buffer[total_bytes_transferred], &*begin, bytes_to_copy);
      total_bytes_transferred += bytes_to_copy;
    }
    if (data.size() < block_size_) {
      // The block was a partial block and thus signals EOF at its upper bound.
      break;
    }
  }
  TF_SetStatus(status, TF_OK, "");
  return total_bytes_transferred;
}

bool RamFileBlockCache::ValidateAndUpdateFileSignature(

std::string ModularFileSystemTest::cloud_path_;
std::string ModularFileSystemTest::tmp_dir_;

// As some of the implementations might be missing, the tests should still pass
// if the returned `Status` signals the unimplemented state.
bool UnimplementedOrReturnsCode(Status actual_status, Code expected_code) {
  Code actual_code = actual_status.code();
  return (actual_code == Code::UNIMPLEMENTED) || (actual_code == expected_code);