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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 get_dispatcher(self):
 """ Get Dispatcher instance from environment :return: :class:`aiogram.Dispatcher` """

        dp = self.request.app[BOT_DISPATCHER_KEY]
        try:
            from aiogram import Bot, Dispatcher
            Dispatcher.set_current(dp)
            Bot.set_current(dp.bot)
        except RuntimeError:
            pass
        return dp