code: func dbStoreBlock(dbTx database.Tx, block *btcutil.Block) error {
  	hasBlock, err := dbTx.HasBlock(block.Hash())
  	if err != nil {
  		return err
  	}
  	if hasBlock {
  		return nil
  	}
  	return dbTx.StoreBlock(block)
  }
docs: // dbStoreBlock stores the provided block in the database if it is not already
  // there. The full block data is written to ffldb.