@Override
  public void fromData(DataInput in) throws IOException, ClassNotFoundException {
    fromDataPre_GEODE_1_1_1_0(in);
    childPrefix = DataSerializer.readString(in);
    childNamespace = DataSerializer.readString(in);
  }
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