human
Solve the following python programming problem given the following code:
@ blueprint.route ('/hint', methods = ['GET']) 
@ api_wrapper 
@ require_login 
@ block_before_competition (WebError ('The competition has not begun yet!')) 
def request_problem_hint_hook() : 
    @ log_action 
    def hint(pid, source) : 
        return None 
source = request.args.get ('source') 
    pid = request.args.get ('pid') 
    if (pid is None) : 
        return WebError ('Please supply a pid.') 
if (source is None) : 
        return WebError ('You have to supply the source of the hint.') 
tid = api.user.get_team () ['tid'] 
    if (tid not in api.problem.get_unlocked_pids (tid)) : 
        return WebError ("Your team hasn't unlocked this problem yet!") 
hint (pid, source) 
    return WebSuccess ('Hint noted.') 

    
    

    Fix the buggy line: if (tid not in api.problem.get_unlocked_pids (tid)) :
assistant
#Here is Python code to fix the buggy line: if (tid not in api.

if (pid not in api.problem.get_unlocked_pids (tid)) :