Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_25800134_4 (director VARCHAR, series__number VARCHAR)
### Question:
How many directors worked on #158?
### Answer:
SELECT COUNT(director) FROM table_25800134_4 WHERE series__number = 158