@OnClose
    public void onClose(final Session session) {
        clearSession(session);
        LOG.warn("websocket close on client[{}]", getClientIp(session));
    }
@Test
    public void testOnClose() {
        websocketCollector.onOpen(session);
        assertEquals(1L, getSessionSetSize());
        doNothing().when(loggerSpy).warn(anyString(), anyString());
        websocketCollector.onClose(session);
        assertEquals(0L, getSessionSetSize());
        assertNull(getSession());
    }