FieldMetaData fmd = meta.getField(fieldName);
if (fmd == null)
throw new ArgumentException(_loc.get("no-named-field",
forClass, fieldName), null, null, false);
Seq seq = _broker.getValueSequence(fmd);
return (seq == null) ? null : new GeneratorImpl(seq, null, _broker,
meta);
} catch (Exception e) {
throw PersistenceExceptions.toPersistenceException(e);
}