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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 __callHandler(self, callback, event, *params):
 """ Calls a "pre" or "post" handler, if set. @type callback: function @param callback: Callback function to call. @type event: L{ExceptionEvent} @param event: Breakpoint hit event. @type params: tuple @param params: Parameters for the callback function. """

        if callback is not None:
            event.hook = self
            callback(event, *params)