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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_composition_collection(self, composition_id):
 """Returns a Mongo Collection and Composition given a Composition Id"""

        collection = JSONClientValidated('repository',
                                         collection='Composition',
                                         runtime=self._runtime)
        composition_map = collection.find_one({'_id': ObjectId(composition_id.get_identifier())})
        if 'assetIds' not in composition_map:
            raise errors.NotFound('no Assets are assigned to this Composition')
        return composition_map, collection