ring or an array of bytes</li>
            <li><code>key</code> - for an object, the key of the property this message was created from</li>
            <li><code>len</code> - the length of each message when split using a fixed length value</li>
        </ul>
        </dd>
        <dt class="optional">complete</dt>
        <dd>If set, the node will append the payload, and then send the output message in its current state.
            If you don't wish to append the payload, delete it from the msg.</dd>
     