/**
* Checks if a context node is a valid XDI entity.
*
* @param contextNode The context node to check.
* @return True if the context node is a valid XDI entity.
*/
public static boolean isValid(ContextNode contextNode) {
if (contextNode == null) throw new NullPointerException();
if (XdiEntitySingleton.isValid(contextNode)) return true;
if (XdiEntityInstanceUnordered.isValid(contextNode)) return true;
if (XdiEntityInstanceOrdered.isValid(contextNode)) return true;
return false;
}
