code: def stretch(iterable, n=2):
      r
      times = range(n)
      for item in iterable:
          for i in times: yield item
docs: r"""Repeat each item in `iterable` `n` times.
  
      Example:
  
      >>> list(stretch(range(3), 2))
      [0, 0, 1, 1, 2, 2]