How many books are in the series about Katniss Everdeen?
{'directed': True, 'multigraph': False, 'graph': {}, 'nodes': [{'type': 'INTERNAL', 'name_': 'Q1860', 'id': 0, 'label': 'English'}, {'type': 'ANSWER_CANDIDATE_ENTITY', 'name_': 'Q201', 'id': 1, 'label': '3'}, {'type': 'INTERNAL', 'name_': 'Q10307713', 'id': 2, 'label': 'The Hunger Games: Mockingjay – Part 2'}, {'type': 'QUESTIONS_ENTITY', 'name_': 'Q2071301', 'id': 3, 'label': 'Katniss Everdeen'}, {'type': 'INTERNAL', 'name_': 'Q115647497', 'id': 4, 'label': 'Destiny Amaka'}], 'links': [{'name_': 'P364', 'source': 2, 'target': 0, 'label': 'original language of performance work'}, {'name_': 'P674', 'source': 2, 'target': 3, 'label': 'characters'}, {'name_': 'P1412', 'source': 4, 'target': 0, 'label': 'languages spoken, written or signed'}, {'name_': 'P3373', 'source': 4, 'target': 1, 'label': 'sibling'}]}