Expand all tree nodes
Examples
Sample
<button onclick="tree.expandAll()" class="gj-button-md">Expand All</button>
<button onclick="tree.collapseAll()" class="gj-button-md">Collapse All</button>
<br/>
<div id="tree" data-source="/Locations/Get"></div>
<script>
var tree = $('#tree').tree();
</script>