parameters = new HashMap<String, String>();
parameters.put(CLIENT_MAX_WINDOW, null);
parameters.put(CLIENT_NO_CONTEXT, null);
// execute
extension = handshaker.handshakeExtension(
new WebSocketExtensionData(PERMESSAGE_DEFLATE_EXTENSION, Collections.<String, String>emptyMap()));
// test
assertNotNull(extension);
assertEquals(WebSocketServerExtension.RSV1, extension.rsv());