متد call چکار می‌کنه؟

function add(first, second, third) {
  this.result = first + second + third;
}

const item1 = { result: 0 }
const item2 = { result: 0 }
const item3 = { result: 0 }

add.call(item1, 3, 2, 1);
add.call(item2, 9, 3, 2);
add.call(item3, 6, 1, 3);

alert(item1.result); // 6
alert(item2.result); // 14
alert(item3.result); // 10