@After
  public void after() {
    nettyByteBufLeakHelper.afterTest();
  }
Tests functionality of {@link NettyResponseChannel}.
<p/>
To understand what each {@link TestingUri} is doing, refer to
{@link MockNettyMessageProcessor#handleRequest(HttpRequest)} and
{@link MockNettyMessageProcessor#handleContent(HttpContent)}.
ambry-rest/src/test/java/com/github/ambry/rest/NettyResponseChannelTest.java