code: func (c Client) GetBalance() (float64, error) {
  	balance := map[string]string{}
  	if err := c.Get("account/balance", nil, &balance); err != nil {
  		return 0.0, err
  	}
  	balanceFloat, err := strconv.ParseFloat(balance["amount"], 64)
  	if err != nil {
  		return 0, err
  	}
  	return balanceFloat, nil
  }
docs: // GetBalance returns current balance in BTC