human
Solve the following python programming problem given the following code:
def test_update_progress_within_bounds(self) : 
    values = [0.0, 0.5, 1.0] 
    result = [] 
    def progress_callback(event_type, details) : 
        result.append (details.pop ('progress')) 
a_task = ProgressTask () 
    a_task.notifier.register (task.EVENT_UPDATE_PROGRESS, <MASK>) 
    a_task.execute (values) 
    self.assertEqual (values, result) 
    
    Given the code above, what is a proper replacement for <MASK>?
assistant
#Here is a proper replacement for <MASK>.
def progress_callback(