human
Solve the following python programming problem given the following code:
def test_tuple_of_decorators(self) : 
    '
        @method_decorator can accept a tuple of decorators.
        ' 
    def add_question_mark(func) : 
        def _wrapper(* args, **kwargs) : 
            return (func (* args, ** kwargs) + '?') 
return _wrapper 
def add_exclamation_mark(func) : 
        def _wrapper(* args, **kwargs) : 
            return (func (* args, ** kwargs) + '!') 
return _wrapper 
decorators = (<MASK>, add_question_mark) 
    @ method_decorator (decorators, name = 'method') 
    class TestFirst (object) : 
        def method(self) : 
            return 'hello world' 
class TestSecond (object) : 
        @ method_decorator (decorators) 
        def method(self) : 
            return 'hello world' 
self.assertEqual (TestFirst ().method (), 'hello world?!') 
    self.assertEqual (TestSecond ().method (), 'hello world?!') 
    
    Given the code above, what is a proper replacement for <MASK>?
assistant
#Here is a proper replacement for <MASK>.
def add_exclamation_mark(