EventLoopGroup getSharedOrCreateEventLoopGroup(EventLoopGroup eventLoopGroupShared) {
        if (eventLoopGroupShared != null) {
            return eventLoopGroupShared;
        }
        return this.eventLoopGroup = new NioEventLoopGroup();
    }
@Test
    public void givenNull_whenGetEventLoop_ThenReturnShared() {
        eventLoop = client.getSharedOrCreateEventLoopGroup(null);
        assertThat(eventLoop, instanceOf(NioEventLoopGroup.class));
    }