@Description("compute sha256 hash")
    @ScalarFunction
    @SqlType(StandardTypes.VARBINARY)
    public static Slice sha256(@SqlType(StandardTypes.VARBINARY) Slice slice)
    {
        return computeHash(Hashing.sha256(), slice);
    }
@Test
    public void testSha256()
    {
        assertFunction("sha256(CAST('' AS VARBINARY))", VARBINARY, sqlVarbinaryHex("E3B0C44298FC1C149AFBF4C8996FB92427AE41E4649B934CA495991B7852B855"));
        assertFunction("sha256(CAST('hashme' AS VARBINARY))", VARBINARY, sqlVarbinaryHex("02208B9403A87DF9F4ED6B2EE2657EFAA589026B4CCE9ACCC8E8A5BF3D693C86"));
    }