AX 2012 - Set voucher to LedgerJournalTrans table

When use AXLedgerJournalTrans class, voucher set as automatically. But if you add record directly to table you have to set voucher:

numberSeq   = numberSeq::newGetVoucherFromCode(NumberSequenceTable::find(ledgerJournalTable.ledgerJournalName().NumberSequenceTable).NumberSequence);
 LedgerJournalTrans.Voucher     = numberSeq.voucher();