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_160728_4 (network VARCHAR, channel VARCHAR)
### Question:
How many networks are there that have a channel number 7?
### Answer:
SELECT COUNT(network) FROM table_160728_4 WHERE channel = 7