App\Models\Store\Product::inStock PHP Method

    public function inStock($quantity = 1, $includeVariations = false)
    {
        $inStock = $this->stock === null || $this->stock >= $quantity;
        if ($inStock === false && $includeVariations === true) {
            $inStock = ($this->masterProduct ?? $this)->variations->contains(function ($variation) use($quantity) {
                return $variation->inStock($quantity);
            });
        }
        return $inStock;
    }