public function __construct($amount, $taxable = false, $options = [])
{
$this->amount = floatval($amount);
$this->taxable = $taxable;
$this->tax = isset($options['tax']) ? $options['tax'] == 0 ? config('laracart.tax') : $options['tax'] : config('laracart.tax');
$this->options = $options;
}