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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 add_sources(self, source_info_dict):
 """Add all of the sources in source_info_dict to this factory """

        self._source_info_dict.update(source_info_dict)
        for key, value in source_info_dict.items():
            self._sources.update(make_sources(key, value))