p:treeNode element is not getting displayed in primefaces

Question

My requirement is to display the tree node element in the xhtml page. But the element is not displayed.

Here is the code

test.xhtml

<p:tree selectionMode="checkbox" >    
<p:treeNode>  
        <h:outputText value="Have a nice day "/>  
 </p:treeNode>
<p:treeNode>  
        <h:outputText value="Good Morning"/>  
 </p:treeNode>
</p:tree>