EventCode

class Event:
    """An abstraction for events."""
    def __init__(self, aReason, aCallback):
        """Construct the instance."""
        self.__reason = aReason
        self.__callback = aCallback
        return

    def getReason(self):
        """Returns the reason that the event is interested in."""
        return self.__reason

    def getCallback(self):
        """Returns the method to invoke for the event."""
        return self.__callback

    def execute(self, aReason):
        """Execute the event for the given model."""
        self.getCallback().execute(aReason)
        return