text: const map = (arr, func) => {
      
  }
  
  // testing if it works:
  
  // Should be [2, 4, 6]
  console.log(map([1, 2, 3], x => x * 2));
  
  // Should be [-5, -6, -7, -8, -9, -10]
  console.log(map([5, 6, 7, 8, 9, 10], x => -x));
  
  // Should be ['A', 'B', 'C', 'D']
  console.log(map(['a', 'b', 'c', 'd'], x => x.toUpperCase()));