old_contents: #!/usr/bin/env python2
  
  from PrinterApplication import PrinterApplication
  
  app = PrinterApplication()
  app.run()
new_contents: #!/usr/bin/env python2
  
  from PrinterApplication import PrinterApplication
  
  app = PrinterApplication.getInstance()
  app.run()
  
subject: Use the PrintApplication's getInstance method to instantiate the printer application