code: func (db *DB) HMget(key []byte, args ...[]byte) ([][]byte, error) {
  	var ek []byte
  
  	it := db.bucket.NewIterator()
  	defer it.Close()
  
  	r := make([][]byte, len(args))
  	for i := 0; i < len(args); i++ {
  		if err := checkHashKFSize(key, args[i]); err != nil {
  			return nil, err
  		}
  
  		ek = db.hEncodeHashKey(key, args[i])
  
  		r[i] = it.Find(ek)
  	}
  
  	return r, nil
  }
docs: // HMget gets multi values of fields