Example 6-18. The parameter in the first call to iterator.next() is always ignored

// Same function* counter as previous example
function* counter(increment) {
	var count = 0;
	increment = increment || 1;
	while (true) {
		count = count + increment;
		increment = (yield count) || increment;
	}
}

var iterator = counter(5); // <- Initial increment is 5
console.log(iterator.next(3).value); // 5 <- 3 is ignored
console.log(iterator.next().value); // 10
console.log(iterator.next(200).value); // 210 <- Increment by 200
console.log(iterator.next().value); // 410