code: def make_dummy_tuples(chars='abcde'):
      
      Quux = namedtuple('Quux', ['x', 'y'])
      some_tuples = [Quux((c*2).upper(), c*2) for c in chars]
      return some_tuples
docs: Helper function to create a list of namedtuples which are useful
      for testing and debugging (especially of custom generators).
  
      Example
      -------
      >>> make_dummy_tuples(chars='abcd')
      [Quux(x='AA', y='aa'),
       Quux(x='BB', y='bb'),
       Quux(x='CC', y='cc'),
       Quux(x='DD', y='dd')]