There are two table header rows, what is the script to copy these two rows as normal rows?

If the table header row is only one row, this script seems to work.
But if there are two table header rows, this header is again basically dizzy and hopeless.

dupeTopRow(myTable);
	myTable.rows.add(LocationOptions.BEFORE, myTable.rows[0]);
/**
* duplicate the first row af a myTable 
* @ param the myTable 
* @ return void 
*/
function dupeTopRow(t){
    var newRow = t.rows.add(LocationOptions.BEFORE, t.rows[0]);
    var newCell = newRow.cells
    var lr = t.rows[1].cells
    for (var i = 0; i < newCell.length; i++){
        newCell[i].properties = lr[i].properties;
    };