code: def deprecated(func: Callable) -> Callable:
      
      @functools.wraps(func)
      def _new_func(*args: Any, **kwargs: Any) -> Any:
          warnings.simplefilter('always', DeprecationWarning)  # turn off filter
          warnings.warn("Call to deprecated function {}.".format(func.__name__),
                        category=DeprecationWarning,
                        stacklevel=2)
          warnings.simplefilter('default', DeprecationWarning)  # reset filter
          return func(*args, **kwargs)
      return _new_func
docs: This is a decorator which can be used to mark functions
      as deprecated. It will result in a warning being emitted
      when the function is used.