human
Solve the following python programming problem given the following code:
@ classmethod 
def get_or_insert(cls, key_name, **kwargs) : 
    def txn() : 
        entity = cls.get_by_key_name (key_name, parent = kwargs.get ('parent')) 
        if (entity is None) : 
            entity = cls (key_name = key_name, ** kwargs) 
            entity.put () 
return entity 
return db.run_in_transaction (key_name) 

    
    

    Fix the buggy line: return db.run_in_transaction (key_name)
assistant
#Here is Python code to fix the buggy line: return db.

return db.run_in_transaction (def txn()