Appreciate to Microsoft developers for un-imaginable very easy concept in Dynamic AX – Complete intitialization, condition & incrementation as datasource in Dynamic AX

Ref:
Form vendInvoiceJournal
method:printTaxUnrealizedInvoice

Here initialization as first record in the data source;
condition as complete data source;
increment as next record in the data source;

    for (vendInvoiceJourLocal = getFirstSelection(vendInvoiceJour_ds);
         vendInvoiceJourLocal;
         vendInvoiceJourLocal = vendInvoiceJour_ds.getNext())

//Brilliant Microsoft developer developed above syntax- but very simple which we cant imagine on normal

Regards,