How to Insert a New LotSerial Row in On Save Sales Order Extension

Hello,

I’m working on a Sales Order On Save OM extension where I need to manage LotSerial information for order lines. My current goals are:

1. Update existing LotSerial rows (e.g., set LotNumber, Locator, etc.).
2. Insert a new LotSerial row if none exists.

Here’s a simplified version of my code for updating:

def lines = header.getAttribute("Lines")
while (lines.hasNext()) {    
 def line = lines.next()      
 def lotSerials = line.getAttribute("LotSerial")     
 while (lotSerials.hasNext()) {          
   def lot = lotSerials.next()             
   lot.setAttribute("LotNumber", "L1")             
   lot.setAttribute("LocatorIdentifier", new BigDecimal("300000310791418"))      
 }
}

This works fine for updating existing LotSerial rows.

However, when I try to