text: function add(a, b) {
    return a + b;
  }
  
  function sum() {
    let numbers = Array.from(arguments);
    let sum = 0;
    numbers.forEach(num => sum += num);
    return sum;
  }
  
  // testing
  console.log(add(10, 6)); // 16
  console.log(sum(10, 5, 6)); // 21
  