// Ваш код здесь

Array.prototype.myIncludes = myIncludes;
 
function myIncludes(el) {
  for (let i = 0; i < this.length; i++) {
    if (el === this[i]) {
      return true;
    }
  }
  return false;
}
 
[1, 2, 3].myIncludes("cat")[(1, 2, 3, "cat")].myIncludes("cat");