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