How to have KendoPanel's all the sections expand

I just started using KendoPanel and I am wanting to expand all the segments of the panel under certain condition. I am using following code to achieve that:

var panelbar = $("#KendoPanel").kendoPanelBar();
                    var kendoPanelbar = panelbar.data().kendoPanelBar;
                    kendoPanelbar.collapse($("li", panelbar.element));

Seems like it is contracting all the segments instead of expanding them. What am I doing wrong?

Please try with below code snippet.

<ul id="mypanelbar">
    <li class="k-state-active">First Item
                <ul>
                    <li>Sub Item 1</li>
                    <li>Sub Item 2</li>
                    <li>Sub Item 3</li>
                    <li>Sub Item 4</li>
                </ul>
    </li>
    <li>Second Item
                <ul>
                    <li>Sub Item 1</li>
                    <li>Sub Item 2</li>
                    <li>Sub Item 3</li>
                    <li>Sub Item 4</li>
                </ul>
    </li>
    <li>Third Item
                <ul>
                    <li>Sub Item 1</li>
                    <li>Sub Item 2</li>
                    <li>Sub Item 3</li>
                    <li>Sub Item 4</li>
                </ul>
    </li>
    <li>Fourth Item
                <ul>
                    <li>Sub Item 1</li>
                    <li>Sub Item 2</li>
                    <li>Sub Item 3</li>
                    <li>Sub Item 4</li>
                </ul>
    </li>
    <li>Fifth Item
                <ul>
                    <li>Sub Item 1</li>
                    <li>Sub Item 2</li>
                    <li>Sub Item 3</li>
                    <li>Sub Item 4</li>
                </ul>
    </li>
</ul>

<script>
    var panelBar;
    $(document).ready(function () {
        panelBar = $("#mypanelbar").kendoPanelBar().data("kendoPanelBar");
        // Expand all item
        panelBar.expand($("#mypanelbar li.k-item"));
    });
</script>

Let me know if any concern.