human
Solve the following python programming problem given the following code:
@ contextmanager 
def capture_registrations() : 
    "Testing utility for capturing registrations.

    :param confirmation_sent_at: An optional datetime object to set the
                                 user's `confirmation_sent_at` to
    " 
    registrations = [] 
    def _on(app, **data) : 
        registrations.append (data) 
user_registered.connect (_on) 
    try : 
        (yield _on) 
finally : 
        user_registered.disconnect (_on) 

    
    

    Fix the buggy line: (yield _on)
assistant
#Here is Python code to fix the buggy line: (yield _on)
.

(yield registrations)