private void releaseCachedItem() {
            synchronized (this) {
                final Object item = this.item;
                if (item instanceof DataBuffer) {
                    DataBufferUtils.release((DataBuffer) item);
                }
                this.item = null;
            }
        }
The actual writeSubscriber from the HTTP server adapter.
spring/boot3-webflux-autoconfigure/src/main/java/com/linecorp/armeria/spring/web/reactive/ChannelSendOperator.java