code: def _GetFileSystemCacheIdentifier(self, path_spec):
      
      string_parts = []
  
      string_parts.append(getattr(path_spec.parent, 'comparable', ''))
      string_parts.append('type: {0:s}'.format(path_spec.type_indicator))
  
      return ''.join(string_parts)
docs: Determines the file system cache identifier for the path specification.
  
      Args:
        path_spec (PathSpec): path specification.
  
      Returns:
        str: identifier of the VFS object.