storage/mysql: mark test helpers
storage/mysql: mark test helpers
AlCutter/trillian,AlCutter/trillian,gdbelvin/trillian,google/trillian,Martin2112/trillian,daviddrysdale/trillian,daviddrysdale/trillian,RJPercival/trillian,gdbelvin/trillian,gdbelvin/trillian,RJPercival/trillian,Martin2112/trillian,daviddrysdale/trillian,google/trillian,Martin2112/trillian