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_55 (rank VARCHAR, years_until_mandatory_retirement VARCHAR)
### Question:
what rank has years until mandatory retirement of 6 years?
### Answer:
SELECT rank FROM table_name_55 WHERE years_until_mandatory_retirement = "6 years"