human
Solve the following python programming problem given the following code:
@ pytest.fixture (scope = 'function') 
def testapp(request, app) : 
    'Return basic Flask app with an established app context.' 
    ctx = app.app_context () 
    ctx.push () 
    def teardown() : 
        ctx.pop () 
request.addfinalizer (ctx) 
    return app 

    
    

    Fix the buggy line: request.addfinalizer (ctx)
assistant
#Here is Python code to fix the buggy line: request.

request.addfinalizer (def teardown()