Write SQL query to solve given problem: State the name of director for the 'Treehouse of Horror XIX' episode.. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT T2.person FROM Episode AS T1 INNER JOIN Credit AS T2 ON T1.episode_id = T2.episode_id WHERE T1.title = 'Treehouse of Horror XIX' AND T2.role = 'director';