Question: what was the purpose of the league of nations after ww1
[{'answer': 'to maintain world peace', 'provenance': [{'wikipedia_id': '17926', 'title': 'League of Nations', 'start_paragraph_id': 1, 'start_character': 341, 'end_paragraph_id': 1, 'end_character': 364, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '17926', 'title': 'League of Nations', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 660, 'bleu_score': 0.6064499437050741, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6526178283228993174}, 'section': 'Section::::Abstract.'}]}]