code: func (nDB *NetworkDB) SetKey(key []byte) {
  	logrus.Debugf("Adding key %.5s", hex.EncodeToString(key))
  	nDB.Lock()
  	defer nDB.Unlock()
  	for _, dbKey := range nDB.config.Keys {
  		if bytes.Equal(key, dbKey) {
  			return
  		}
  	}
  	nDB.config.Keys = append(nDB.config.Keys, key)
  	if nDB.keyring != nil {
  		nDB.keyring.AddKey(key)
  	}
  }
docs: // SetKey adds a new key to the key ring