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_name_4 (surface VARCHAR, tournament VARCHAR)
### Question:
What is Surface, when Tournament is "Sunderland , United Kingdom"?
### Answer:
SELECT surface FROM table_name_4 WHERE tournament = "sunderland , united kingdom"