JavaScript generator-yeild-next()

function* gen() {

  yield 1;

  yield 2;

  yield 3;

}

var g = gen(); // "Generator { }"

g.next();      // "Object { value: 1, done: false }"

g.next();      // "Object { value: 2, done: false }"

g.next();      // "Object { value: 3, done: false }"

g.next();      // "Object { value: undefined, done: true }"