new_contents: # Copyright (C) 2016 by Per Unneberg
  # Helper functions for filetypes
  import os
  try:
      from pytest_ngsfixtures import ROOT_DIR
  except:
      ROOT_DIR = os.curdir
  
  MAPPING = {
      'bai': "PUR.HG00731.tiny.sort.bai",
      'bam': "PUR.HG00731.tiny.sort.bam",
  }
      
  def filetype_mapping(ft, end="pe"):
      """Retrieve mapping for filetype to fixture file name.
  
      Params:
        ft (str): filetype
        end (str): sequencing mode
  
      Returns:
        str: fixture file names
      """
      if ft is None:
          return None
      try:
          fn = os.path.join(ROOT_DIR, "data", "applications", end, MAPPING[ft])
      except Exception as e:
          raise e
      return fn
  
  
subject: Add filetypes test helper function