private void flushPendingWrites(PendingWrites pendingWrites) {
        for (;;) {
            final Entry<HttpObject, ChannelPromise> e = pendingWrites.poll();
            if (e == null) {
                break;
            }

            write(e.getKey(), e.getValue());
        }
    }
The map which maps a request ID to its related pending response.
core/src/main/java/com/linecorp/armeria/internal/common/Http1ObjectEncoder.java