old_contents: #!/usr/bin/env python
  
  screen = xfce4.netk.screen_get_default()
  screen.get_windows()
  screen.get_windows()
  
  # no segfault
  
new_contents: #!/usr/bin/env python
  
  import xfce4
  
  screen = xfce4.netk.screen_get_default()
  screen.get_windows()
  screen.get_windows()
  
  # no segfault
  
subject: add missing import