How to append a row to particular section in Titanium

app.js

(function() {
    var win = Ti.UI.createWindow();
    var section1 = Ti.UI.createTableViewSection({
        headerTitle:'Header 1'
    });
    for (var i=0; i < 4; i++) {
        section1.add(Ti.UI.createTableViewRow({
            title:'Row '+i
        }));
    }

    var section2 = Ti.UI.createTableViewSection({
        headerTitle:'Header 2'
    });
    for (i=4; i < 10; i++) {
        section2.add(Ti.UI.createTableViewRow({
            title:'Row '+i
        }));
    }

    var tv = Ti.UI.createTableView({
        data:[section1,section2]
    });
    
    function appendRowToSection(tableView, row, sectionIndex) {
        var sections = tableView.data;
        if (!sections || sections.length < sectionIndex || isNaN(+sectionIndex)) {
            return;
        }
        sections[sectionIndex].add(row);
        tableView.setData(sections);
    }
    
    win.add(tv);
    
    tv.addEventListener("click", function() {
        appendRowToSection(tv, Ti.UI.createTableViewRow({ title: "new row"}), 0);
    });
    
    win.open();
})();