<p:tree and expanded

[RAHILE]

Hello
Environment: 2.1 PRIMEFACES tomcat6
Here is my code:
public class Visit implements Serializable {
public TreeNode treeBean() {
TreeNode root;
root = new DefaultTreeNode("Root", null);
TreeNode node0 = new DefaultTreeNode("Node 0", root);
TreeNode node1 = new DefaultTreeNode("Node 1", root);

TreeNode node2 = new DefaultTreeNode("Node 2", root);

TreeNode node00 = new DefaultTreeNode("Node 0.0", node0);
TreeNode node01 = new DefaultTreeNode("Node 0.1", node0);
node0.setExpanded(true);
//node00.setExpanded(true);
node01.setExpanded(true);

TreeNode node10 = new DefaultTreeNode("Node 1.0", node1);
TreeNode node11 = new DefaultTreeNode("Node 1.1", node1);
TreeNode node000 = new DefaultTreeNode("fils","Node 0.0.0", node00);
TreeNode node001 = new DefaultTreeNode("Node 0.0.1", node00);
TreeNode node010 = new DefaultTreeNode("Node 0.1.0", node01);

TreeNode node100 = new DefaultTreeNode("Node 1.0.0", node10);
return root ;
} ;

}
<h:form prependId="false">

<p:tree value="#{visit.treeBean()}" var="node"
dynamic="true"
cache="false">
<p:treeNode>
<h:outputText value="#{node}" />
</p:treeNode>
<p:treeNode type = "fils" >
<p:commandLink ajax="true" value = "#{node}" update="carDetail" ondblclick="carDialog.show()" >
</p:commandLink>
</p:treeNode>

</p:tree>
</h:form>
when I enable the following line: node00.setExpanded(true);

Page does not display my device TreeNode
thank you for your support