code: func dbFetchUtxoEntryByHash(dbTx database.Tx, hash *chainhash.Hash) (*UtxoEntry, error) {
  	// Attempt to find an entry by seeking for the hash along with a zero
  	// index.  Due to the fact the keys are serialized as <hash><index>,
  	// where the index uses an MSB encoding, if there are any entries for
  	// the hash at all, one will be found.
  	cursor := dbTx.Metadata().Bucket(utxoSetBucketName).Cursor()
  	key := outpointKey(wire.OutPoint{Hash: *hash, Index: 0})
  	ok := cursor.Seek(*key)
  	recycleOutpointKey(key)
  	if !ok {
  		return nil, nil
  	}
  
  	// An entry was found, but it could just be an entry with the next
  	// highest hash after the requested one, so make sure the hashes
  	// actually match.
  	cursorKey := cursor.Key()
  	if len(cursorKey) < chainhash.HashSize {
  		return nil, nil
  	}
  	if !bytes.Equal(hash[:], cursorKey[:chainhash.HashSize]) {
  		return nil, nil
  	}
  
  	return deserializeUtxoEntry(cursor.Value())
  }
docs: // dbFetchUtxoEntryByHash attempts to find and fetch a utxo for the given hash.
  // It uses a cursor and seek to try and do this as efficiently as possible.
  //
  // When there are no entries for the provided hash, nil will be returned for the
  // both the entry and the error.