@Test
public void testWriteOneOutbound() throws InterruptedException {

    final CountDownLatch latch = new CountDownLatch(1);
    final AtomicInteger flushCount = new AtomicInteger(0);
    EmbeddedChannel channel = new EmbeddedChannel(new ChannelOutboundHandlerAdapter() {
        @Override
        public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
            ctx.write(msg, promise);
            latch.countDown();
        }
        @Override
        public void flush(ChannelHandlerContext ctx) throws Exception {
            flushCount.incrementAndGet();
        }
    });
    // This shouldn't trigger a #flush()
    channel.writeOneOutbound("Hello, Netty!");
    if (!latch.await(1L, TimeUnit.SECONDS)) {
        fail("Nobody called #write() in time.");
    }
    channel.close().syncUninterruptibly();
    // There was no #flushOutbound() call so nobody should have called #flush()
    assertEquals(0, flushCount.get());
}