in src/main/java/com/twitter/http2/HttpStreamEncoder.java [268:278]
public void operationComplete(ChannelFuture future) throws Exception {
if (future.isSuccess()) {
ctx.writeAndFlush(msg, promise);
} else if (future.isCancelled()) {
ReferenceCountUtil.release(msg);
promise.cancel(true);
} else {
ReferenceCountUtil.release(msg);
promise.setFailure(future.cause());
}
}