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 customer_contact_channels (channel_code VARCHAR, customer_id VARCHAR)
### Question:
List all the contact channel codes that were used less than 5 times.
### Answer:
SELECT channel_code FROM customer_contact_channels GROUP BY channel_code HAVING COUNT(customer_id) < 5