### Question:
VertxServerWebSocket extends AbstractServerWebSocket { @Override public <T> T unwrap(Class<T> clazz) { return org.vertx.java.core.http.ServerWebSocket.class.isAssignableFrom(clazz) ? clazz.cast(socket) : null; } VertxServerWebSocket(org.vertx.java.core.http.ServerWebSocket socket); @Override String uri(); @Override T unwrap(Class<T> clazz);  }### Answer:
@Test public void unwrap() { performer.onserver(new Action<ServerWebSocket>() { @Override public void on(ServerWebSocket ws) { assertThat(ws.unwrap(org.vertx.java.core.http.ServerWebSocket.class), instanceOf(org.vertx.java.core.http.ServerWebSocket.class)); performer.start(); } }) .connect(); }