ge handlers handle which of the native websocket
 message types please see <a href="../../javax/websocket/MessageHandler.Whole.html" title="interface in javax.websocket"><code>MessageHandler.Whole</code></a> and <a href="../../javax/websocket/MessageHandler.Partial.html" title="interface in javax.websocket"><code>MessageHandler.Partial</code></a>.
 Adding more than one of any one type will result in a runtime exception.
 <p>
 This method is not safe to use unless you are providing an anonymous class derived