code: func (c *Config) AccountConfig() (int, int, string, error) {
  	scryptN := keystore.StandardScryptN
  	scryptP := keystore.StandardScryptP
  	if c.UseLightweightKDF {
  		scryptN = keystore.LightScryptN
  		scryptP = keystore.LightScryptP
  	}
  
  	var (
  		keydir string
  		err    error
  	)
  	switch {
  	case filepath.IsAbs(c.KeyStoreDir):
  		keydir = c.KeyStoreDir
  	case c.DataDir != "":
  		if c.KeyStoreDir == "" {
  			keydir = filepath.Join(c.DataDir, datadirDefaultKeyStore)
  		} else {
  			keydir, err = filepath.Abs(c.KeyStoreDir)
  		}
  	case c.KeyStoreDir != "":
  		keydir, err = filepath.Abs(c.KeyStoreDir)
  	}
  	return scryptN, scryptP, keydir, err
  }
docs: // AccountConfig determines the settings for scrypt and keydirectory