What is the Opponent of the Banja Luka Tournament with a Score of 4 6, 4 6?
CREATE TABLE table_name_57 (
    opponent VARCHAR,
    score VARCHAR,
    tournament VARCHAR
)
SELECT opponent FROM table_name_57 WHERE score = "4–6, 4–6" AND tournament = "banja luka"
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: What is the Opponent of the Banja Luka Tournament with a Score of 4 6, 4 6? ### Input: CREATE TABLE table_name_57 (
    opponent VARCHAR,
    score VARCHAR,
    tournament VARCHAR
) ### Response: SELECT opponent FROM table_name_57 WHERE score = "4–6, 4–6" AND tournament = "banja luka"