Javascript Iterator Early Termination

class Counter {/*from   w  w  w  .ja  va 2  s  .co  m*/
    constructor(limit) {
        this.limit = limit;
    }

    [Symbol.iterator]() {
        let count = 1,
            limit = this.limit;
        return {
            next() {
                if (count <= limit) {
                    return {
                        done: false,
                        value: count++
                    };
                } else {
                    return {
                        done: true
                    };
                }
            },
            return () {
                console.log('Exiting early');
                return {
                    done: true
                };
            }
        };
    }
}

let counter1 = new Counter(5);

for (let i of counter1) {
    if (i > 2) {
        break;
    }
    console.log(i);
}
// 1 
// 2 
// Exiting early 


let counter2 = new Counter(5);

try {
    for (let i of counter2) {
            if (i > 2) {
                throw 'err';
            }
            console.log(i);
        }
}catch (e) {}
// 1 
// 2 
// Exiting early 


let counter3 = new Counter(5);

let [a, b] = counter3;
// Exiting early