code: func (s *Store) EnsureConfigEntry(idx uint64, conf structs.ConfigEntry) error {
  	tx := s.db.Txn(true)
  	defer tx.Abort()
  
  	if err := s.ensureConfigEntryTxn(tx, idx, conf); err != nil {
  		return err
  	}
  
  	tx.Commit()
  	return nil
  }
docs: // EnsureConfigEntry is called to do an upsert of a given config entry.