code: func dbFetchHeaderByHeight(dbTx database.Tx, height int32) (*wire.BlockHeader, error) {
  	hash, err := dbFetchHashByHeight(dbTx, height)
  	if err != nil {
  		return nil, err
  	}
  
  	return dbFetchHeaderByHash(dbTx, hash)
  }
docs: // dbFetchHeaderByHeight uses an existing database transaction to retrieve the
  // block header for the provided height.