public function getTotalTaxAttribute()
    {
        if (empty($this->shopCalculations)) $this->runCalculations();
        return round($this->shopCalculations->totalTax + ($this->totalPrice * Config::get('shop.tax')), 2);
    }
public function getTotalTaxAttribute()
    {
        if (empty($this->shopCalculations)) $this->runCalculations();
        return round($this->shopCalculations->totalTax + ($this->totalPrice * Config::get('shop.tax')), 2);
    }
Returns total tax of all the items in cart.

@return float