Returns a MutableMap where each value is a Pair that combines the value of the current MutableMap and the provided Traversable

public function zip<Tu>(
  Traversable<Tu> $traversable,
): MutableMap<Tk, Pair<Tv, Tu>>;

If the number of values of the current MutableMap are not equal to the number of elements in the Traversable, then only the combined elements up to and including the final element of the one with the least number of elements is included.

The keys associated with the current MutableMap remain unchanged in the returned MutableMap.