protected Iterable<ByteBuffer> responseContent() {
        return List.of();
    }
<p>Returns an Iterable for the ByteBuffers that the {@link #dispatch(ResponseHandler)} method should write to the
{@link Response} once it has {@link ResponseHandler#handleResponse(Response) connected}. The default
implementation returns an empty list. Because this method uses the Iterable interface, you can provide the
ByteBuffers lazily, or as they become available.</p>

@return The ByteBuffers to write to the Response's ContentChannel.
jdisc_core/src/main/java/com/yahoo/jdisc/handler/ResponseDispatch.java