 this <code>viewId</code>, return
 <code>null</code> instead.
 </p>

 <p>
 This method must consult the context initialization parameter named by the symbolic constant
 <code>StateManager.STATE_SAVING_METHOD_PARAM_NAME</code> to determine whether state should be saved on the client or
 the server. If not present, client side state saving is assumed.
 </p>

 <p>
 If the init parameter indicates that client side state saving should be used, this method must call the
 <code>getTreeStructureToRestore()</code> a