private void writeReadAndAssert(final TimeZone timeZone, final String id)
{
final TimeZoneConverter converter = new TimeZoneConverter();
final String str = converter.toString(timeZone);
assertEquals(id, str);
final TimeZone tz = converter.fromString(str);
if (id == null) {
assertNull(tz);
} else {
assertEquals(id, tz.getID());
}