text: function solve() {
     let addButtons = document.querySelectorAll('.add-product');
     let textArea = document.querySelector('textarea');
     let checkOutButton = document.querySelector('.checkout');
  
     checkOutButton.addEventListener('click', checkout);
  
     for (let button of addButtons) {
        button.addEventListener('click', onClick);
     }
  
     let productList = new Set();
     let totalPrice = 0;
  
     function onClick() {
        let currentProductPrice = this.parentElement.parentElement.getElementsByClassName('product-line-price')[0].textContent;
        let currentProductName = this.parentElement.parentElement.querySelector('div.product-title').textContent;
        let textToAppend = `Added ${currentProductName} for ${currentProductPrice} to the cart.\n`;
        textArea.textContent += textToAppend;
        totalPrice += Number(currentProductPrice);
        productList.add(currentProductName);
     }
  
     function checkout() {
        textArea.textContent += `You bought ${Array.from(productList).join(', ')} for ${totalPrice.toFixed(2)}.\n`;
  
        for (let button of addButtons) {
           button.disabled = true;
        }
  
        checkOutButton.disabled = true;
     }
  }