code: def init_default(self):
          
          import f311
          if self.default_filename is None:
              raise RuntimeError("Class '{}' has no default filename".format(self.__class__.__name__))
          fullpath = f311.get_default_data_path(self.default_filename, class_=self.__class__)
          self.load(fullpath)
          self.filename = None
docs: Initializes object with its default values
  
          Tries to load self.default_filename from default
          data directory. For safety, filename is reset to None so that it doesn't point to the
          original file.