docs: def iterate(iterator, n=None):
      """Efficiently advances the iterator N times; by default goes to its end.
  
      The actual loop is done "in C" and hence it is faster than equivalent 'for'.
  
      :param n: How much the iterator should be advanced.
                If None, it will be advanced until the end.
      """
      ensure_iterable(iterator)
      if n is None:
          deque(iterator, maxlen=0)
      else:
          next(islice(iterator, n, n), None)