Hint
yield* delegates iteration to any iterable — another generator, array, string, etc.
function* inner() { yield 'a'; yield 'b'; }
function* outer() {
yield 1;
yield* inner();
yield 2;
}
console.log([...outer()].join(','));1,a,b,2
Explanation: yield* delegates to inner(). outer yields 1, then all of inner (a, b), then 2.
Key Insight: yield* delegates iteration to any iterable — another generator, array, string, etc.