tensorflow::io::JoinPath(root_dir_, path);
    // We have already checked `GetParam().empty()` in
    // `ModularFileSystemTest()`. root_dir_ should contain `GetParam() + "://"`
    // if it isn't empty.
    return translated_name;
  }

  // Converts absolute paths to paths relative to root_dir_.
  StringPiece GetRelativePath(StringPiece absolute_path) {

// `cond_output` and `body_outputs`.
//
// If `status` is OK, the caller must call either TF_FinishWhile or
// TF_AbortWhile on the returned TF_WhileParams. If `status` isn't OK, the
// returned TF_WhileParams is not valid, and the caller should not call
// TF_FinishWhile() or TF_AbortWhile().
//
// Missing functionality (TODO):
// - Gradients
// - Reference-type inputs