Returns a lazy, access elements only when needed view of the current Pair

public function lazy(): KeyedIterable<int, mixed>;

Normally, memory is allocated for all of the elements of the Pair. With a lazy view, memory is allocated for an element only when needed or used in a calculation like in map() or filter().

That said, Pairs only have two elements. So the performance impact on a Pair will be not be noticeable in the real world.