public function getIterator() { return new LazyMapKeyedIterator($this->iterable->getIterator(), $this->fn); }
public function getIterator() { return new LazyZipKeyedIterator($this->iterable1->getIterator(), $this->iterable2->getIterator()); }
public function getIterator() { return new LazySliceKeyedIterator($this->iterable->getIterator(), $this->start, $this->len); }
public function getIterator() { return new LazyFilterWithKeyIterator($this->iterable->getIterator(), $this->fn); }