new_contents: #!/usr/bin/env python
  # -*- coding: utf-8 -*-
  
  """ Removes lines from .lett file where the last column containing base64
  encoded text is empty. This otherwise leads to problems downstream. """
  
  import sys
  
  for line in sys.stdin:
      if line.split("\t")[-1].strip():
          sys.stdout.write(line)
  
subject: fix broken .lett files