public function format()
    {
        $format = $this->amount();

        if ($this->currency->getSymbol() === null) {
            $format .= ' '.$this->currency->getCode();
        } elseif ($this->currency->getSymbolPlacement() == 'before') {
            $format = $this->currency->getSymbol().$format;
        } else {
            $format .= $this->currency->getSymbol();
        }

        return $format;
    }