new_contents: # -*- coding: utf-8 -*-
  """
  File handling library module.
  """
  import os
  
  
  def check_readable(path):
      """
      Raise assertion error if the given path is not readable.
      """
      assert os.access(path, os.R_OK), "Unable to read from: {}".format(path)
  
  
  def check_writable(path):
      """
      Raise assertion error if the given path is not writable.
      """
      assert os.access(path, os.W_OK),  "Unable to write to: {}".format(path)
  
  
subject: Create file_handling.py