    @Test
    public void onOpen() throws Exception {

        final SockJsService service = mock(SockJsService.class);
        final SockJsSession sockJSSession = new SockJsSession("123", service);
        final SockJsSessionContext session = mock(SockJsSessionContext.class);
        sockJSSession.onOpen(session);
        verify(service).onOpen(session);
        assertThat(sockJSSession.getState(), is(State.OPEN));
    }