presto-main/src/main/java/io/prestosql/type/TimeOperators.java/TimeOperators/castToSlice
class TimeOperators:    @ScalarOperator(CAST)
    @LiteralParameters("x")
    @SqlType("varchar(x)")
    public static Slice castToSlice(ConnectorSession session, @SqlType(StandardTypes.TIME) long value)
    {
        if (session.isLegacyTimestamp()) {
            return utf8Slice(printTimeWithoutTimeZone(session.getTimeZoneKey(), value));
        }

        return utf8Slice(printTimeWithoutTimeZone(value));
    }