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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_level_methods(self, level):
 """ Returns the methods to call for the given level of report :param level: The level of report :return: The set of methods to call to fill the report :raise KeyError: Unknown level or alias """

        try:
            # Real name of the level
            return set(self.__levels[level])
        except KeyError:
            # Alias
            result = set()
            for sub_level in self.__aliases[level]:
                result.update(self.get_level_methods(sub_level))
            return result