+= childNodes[i].mass;
      totalValue = childNodes[i].value
        ? totalValue + childNodes[i].value
        : totalValue;
    }
    clusterOptions.mass = totalMass;
    if (totalValue > 0) {
      clusterOptions.value = totalValue;
    }
    return clusterOptions;
  },
}
</pre>
                </td>
            </tr>
            <tr><td id="event_clusterNodeProperties">clusterNodeProperties</td>
                <td>Object</td>
                <td><i>Optional. </i> This is an object containing the optio