code: def deprecated(func):
      
      def decorated(*args, **kwargs):
          warnings.warn('Call to deprecated function %s.' % func.__name__,
                        category=DeprecationWarning,
                        stacklevel=2)
          return func(*args, **kwargs)
      decorated.__name__ = func.__name__
      decorated.__doc__ = func.__doc__
      decorated.__dict__.update(func.__dict__)
      return decorated
docs: A decorator for marking functions as deprecated. Results in
      a printed warning message when the function is used.