I have an igTree defined as follows. The root node is being populated via the api call, however, no node has the icon so I can expand to view the children for the node. What else must I do to be able to expand a node? How do I tell the node to assume there are children, so include the expander icon?

$("#tree").igTree({
singleBranchExpand: false,
height: "300px",
width: "610px",
checkboxMode: "triState",
loadOnDemand: true,
dataSourceType: "remoteUrl",
dataSourceUrl: "/api/items",
nodePopulating: function (event, ui) {
debugger;
$("#tree").igTree('option', 'dataSourceUrl', '/api/items/' + ui.data.id);
return true;
},
bindings: {
textKey: "Value",
valueKey: "Key",
primaryKey: "Key",
checkedKey: "Checked",
childDataProperty: "items",
}
});