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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def addCallback(cls, eventType, func, record=None, once=False):
 """ Adds a callback method to the class. When an event of the given type is triggered, any registered callback will be executed. :param eventType: <str> :param func: <callable> """

        callbacks = cls.callbacks()
        callbacks.setdefault(eventType, [])
        callbacks[eventType].append((func, record, once))