def __add__(self, newHandler):
        """Used to append handlers to each other"""
        if not isinstance(newHandler, Handler):
            raise TypeError('Handler.__add__() expects Handler')
        if self.nextHandler:
            self.nextHandler + newHandler
        else:
            self.nextHandler = newHandler
            while newHandler:
                newHandler.data = self.data
                newHandler = newHandler.nextHandler
        return self
Used to append handlers to each other
recipes/Python/302422_handler_stack/recipe-302422.py