Multiple Shipping Routes, 2 line items, same address.

newSO.setFieldValue('ismultishipto',"T");

for(var i=0;i<itemInternalIdList.length;i++){

newSO.selectNewLineItem('item');
newSO.setCurrentLineItemValue('item', 'item', itemInternalIdList[i]);
newSO.setCurrentLineItemValue('item', 'quantity', itemQtyList[i]);
newSO.setCurrentLineItemValue('item', 'location', '4');
newSO.setCurrentLineItemValue('item', 'taxcode', '-7');
newSO.setCurrentLineItemValue('item', 'description',itemRefList[i]);
newSO.setCurrentLineItemValue('item', 'shipmethod', '50943');

var subrecord = newSO.createCurrentLineItemSubrecord('item', 'shippingaddress');
subrecord.setFieldValue('label', itemArray[i][nameIndex]);
subrecord.setFieldValue('attention', itemArray[i][nameIndex]);
subrecord.setFieldValue('addressee', itemArray[i][companyIndex]);
subrecord.setFieldValue('addr1', itemArray[i][streetIndex]+" "+itemArray[i][aptIndex]);
subrecord.setFieldValue('city', itemArray[i][cityIndex]);
subrecord.setFieldValue('zip', itemArray[i][zipIndex]);
subrecord.setFieldValue('state', itemArray[i][stateIndex]);