Who wrote the episode with the production code 519?
CREATE TABLE table_21550897_1 (written_by VARCHAR, production_code VARCHAR)
SELECT written_by FROM table_21550897_1 WHERE production_code = 519
### Context: CREATE TABLE table_21550897_1 (written_by VARCHAR, production_code VARCHAR) ### Question: Who wrote the episode with the production code 519? ### Answer: SELECT written_by FROM table_21550897_1 WHERE production_code = 519