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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 __callback(self, data):
 """ Safely calls back a method :param data: Associated stanza """

        method = self.__cb_message
        if method is not None:
            try:
                method(data)
            except Exception as ex:
                _logger.exception("Error calling method: %s", ex)