old_contents: import posixpath
  
  error_msg = '''The index must be a string.'''
  
  def to_path(key):
      return (key,)
  
  def from_path(path):
      return posixpath.join(*path)
  
new_contents: import posixpath
  
  error_msg = '''The index must be a string.'''
  
  def to_path(key):
      return tuple(key.strip('/').split('/'))
  
  def from_path(path):
      return posixpath.join(*path)
  
subject: fix the raw transformer