          save_thread = self.threaded_io("save")
          self.run_extraction()
          save_thread.join()
          self.alignments.save()
          Utils.finalize(self.images.images_found,
                         self.alignments.faces_count,
                         self.verify_output)
  
      def threaded_io(self, task, io_args=None):
          """ Perform I/O task in a background thread """
 
</s>
        Utils.finalize(self.images.images_found // self.skip_num,
          save_thread = self.threaded_io("save")
          self.run_extraction()
          save_thread.join()
          self.alignments.save()
        Utils.finalize(self.images.images_found // self.skip_num,
                         self.alignments.faces_count,
                         self.verify_output)
  
      def threaded_io(self, task, io_args=None):
          """ Perform I/O task in a background thread """
keep keep keep keep replace keep keep keep keep keep
 Extract: Add option to extract faces from every nth frame
scripts/extract.py