Groovy script to create Manual Price Adjustment

Hi,

Is there any method to add Manual Price Adjustment using Groovy? I have tried with the below code in an On-Save extension , but facing an error while trying to save.

while (lines.hasNext()){

        def line = lines.next();

        def mp = line.getAttribute("ManualPriceAdjustments");

        def row = mp.createRow();

        row.setAttribute("AdjustmentAmount",0);

        row.setAttribute("AdjustmentTypeCode","PRICE_OVERRIDE");

        row.setAttribute("ChargeDefinitionCode","QP_SALE_PRICE");

        row.setAttribute("ReasonCode","ORA_OTHER");

        row.setAttribute("SequenceNumber",1);

        mp.insertRow(row);

    }

Best Regards,

Vikram