human
Solve the following python programming problem given the following code:
@ pytest.fixture 
def session(db_engine, request, tmpdir) : 
    models.Model.metadata.drop_all (db_engine) 
    models.Model.metadata.create_all (db_engine) 
    models.Session.configure (bind = db_engine) 
    session = models.Session () 
    models.Fate._all_fates = None 
    def fin() : 
        session.close () 
request.addfinalizer (tmpdir) 
    return session 

    
    

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

request.addfinalizer (def fin()