  void resume_subsequent_commits(wait_for_commit *suspended) {
    DBUG_ASSERT(!wait_for_commit_ptr);
    wait_for_commit_ptr= suspended;
  }
  void resume_subsequent_commits(wait_for_commit *suspended) {
    DBUG_ASSERT(!wait_for_commit_ptr);
    wait_for_commit_ptr= suspended;
  }