When was the Hamaoka-4 unit commercial operation date?
CREATE TABLE table_name_42 (
    commercial_operation VARCHAR,
    unit VARCHAR
)
SELECT commercial_operation FROM table_name_42 WHERE unit = "hamaoka-4"
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: When was the Hamaoka-4 unit commercial operation date? ### Input: CREATE TABLE table_name_42 (
    commercial_operation VARCHAR,
    unit VARCHAR
) ### Response: SELECT commercial_operation FROM table_name_42 WHERE unit = "hamaoka-4"