code: def deprecated(use_instead, notes=None):
      
      if notes is None:
          notes = ""
      else:
          notes = " " + notes
  
      def wrapped_func(func):
          @functools.wraps(func)
          def _inner(*args, **kwargs):
              warnings.simplefilter('always', DeprecationWarning)  # un-filter
              msg = ("{0} is deprecated and will be removed in a future "
                     "release of pmdarima. Use {1} instead.{2}"
                     .format(func.__name__, use_instead, notes))
  
              warnings.warn(
                  msg,
                  category=DeprecationWarning,
                  stacklevel=2)
              warnings.simplefilter('default', DeprecationWarning)  # re-filter
              return func(*args, **kwargs)
          return _inner
      return wrapped_func
docs: Mark functions as deprecated.
  
      This decorator will result in a warning being emitted when the decorated
      function is used.
  
      Parameters
      ----------
      use_instead : str
          The name of the function to use instead.
  
      notes : str, optional (default=None)
          Additional notes to add to the warning message.