new_contents: #!/usr/bin/env python
  """when seconds or nano_seconds was set to 0 rather than None (the default) the
  value would not be reset to 0 but instead the previous value would remain in 
  place
  
  this was only visible if a user had previously set a value
  """
  from butter.timerfd import Timer
  from select import select
  
  def test_f468afef89dTEST_PERIOD():
      TEST_PERIOD = 1
      TIMEOUT = TEST_PERIOD * 2
      
      # create a timer
      timer = Timer()
  
      # set the timer
      timer.offset(seconds=TEST_PERIOD, nano_seconds=TEST_PERIOD)
      timer.repeats(seconds=TEST_PERIOD, nano_seconds=TEST_PERIOD)
      timer.update()
  
      # ensure it fires
      r_fd, _, _ = select([timer], [], [])
  
      # reset and update the timer
      timer.offset(seconds=0, nano_seconds=0)
      timer.repeats(seconds=0, nano_seconds=0)
      timer.update()
      # we set this twice to get the value we set the timer to
      new_val = timer.update()
      
      assert new_val.next_event == (0, 0), 'Timer offset did not get reset'
      assert new_val.period == (0, 0), 'Timer period did not get reset'
      
      # ensure it does not fire
      select([timer], [], [], TIMEOUT)
  
subject: Put a regression test in place for commit f468afef89d1