human
Solve the following python programming problem given the following code:
def _StubWSGIUtils(output_app_holder) : 
    'Stub out WSGI adapters for python 2.5.' 
    stubs = _StubOut () 
    stubbed_wsgi_handler_class = (lambda * args, **kwargs : _MockedWsgiHandler (output_app_holder)) 
    def RunWSGIStub(application) : 
        output_app_holder.append (application) 
stubs.Set (webapp_util, 'run_bare_wsgi_app', RunWSGIStub) 
    stubs.Set (webapp_util, 'run_wsgi_app', RunWSGIStub) 
    stubs.Set (handlers, 'BaseHandler', stubbed_wsgi_handler_class) 
    stubs.Set (handlers, 'SimpleHandler', <MASK>) 
    stubs.Set (handlers, 'BaseCGIHandler', stubbed_wsgi_handler_class) 
    stubs.Set (handlers, 'CGIHandler', stubbed_wsgi_handler_class) 
    return stubs.CleanUp 
    
    Given the code above, what is a proper replacement for <MASK>? Choose among: output_app_holder, stubbed_wsgi_handler_class, RunWSGIStub, stubs
assistant
#Here is a proper replacement for <MASK>.
stubbed_wsgi_handler_class