<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def orify(e, changed_callback):
 """Add another event to the multi_event :param e: the event to be added to the multi_event :param changed_callback: a method to call if the event status changes, this method has access to the multi_event :return: """

    if not hasattr(e, "callbacks"):  # Event has not been orified yet
        e._set = e.set
        e._clear = e.clear
        e.set = lambda: or_set(e)
        e.clear = lambda: or_clear(e)
        e.callbacks = list()
    # Keep track of one callback per multi event
    e.callbacks.append(changed_callback)