CREATE TABLE table_17555 ("Class" TEXT, "Ship Name" TEXT, "Origin" TEXT, "Hull Numbers" FLOAT, "Service years" TEXT, "Previously" TEXT, "Note" TEXT)

who is the class where note is reportedly still active as of 2012?
SELECT "Class" FROM table_17555 WHERE "Note" = 'Reportedly still active as of 2012'
SELECT "Class" FROM "table_17555" WHERE "Note" = 'Reportedly still active as of 2012'