@Override
  public void toData(DataOutput out) throws IOException {
    toDataPre_GEODE_1_1_1_0(out);
    DataSerializer.writeString(childPrefix, out);
    DataSerializer.writeString(childNamespace, out);
  }
Gets the namespace for the child element.

@return XML element namespace for the child element
geode-core/src/main/java/org/apache/geode/management/internal/configuration/domain/XmlEntity.java