code: protected void storeExtension(Extension e, XMLStreamWriter writer, String elementName) throws XMLStreamException
     {
        writer.writeStartElement(elementName);
        writer.writeAttribute(CommonXML.ATTRIBUTE_CLASS_NAME,
                              e.getValue(CommonXML.ATTRIBUTE_CLASS_NAME,
                                                          e.getClassName()));
        if (e.getModuleName() != null)
           writer.writeAttribute(CommonXML.ATTRIBUTE_MODULE_NAME,
                 e.getValue(CommonXML.ATTRIBUTE_MODULE_NAME, e.getModuleName()));
        if (e.getModuleSlot() != null)
           writer.writeAttribute(CommonXML.ATTRIBUTE_MODULE_SLOT,
                 e.getValue(CommonXML.ATTRIBUTE_MODULE_SLOT, e.getModuleSlot()));
  
        if (!e.getConfigPropertiesMap().isEmpty())
        {
           Iterator<Map.Entry<String, String>> it =
              e.getConfigPropertiesMap().entrySet().iterator();
  
           while (it.hasNext())
           {
              Map.Entry<String, String> entry = it.next();
  
              writer.writeStartElement(CommonXML.ELEMENT_CONFIG_PROPERTY);
              writer.writeAttribute(CommonXML.ATTRIBUTE_NAME, entry.getKey());
              writer.writeCharacters(e.getValue(CommonXML.ELEMENT_CONFIG_PROPERTY,
                                                                 entry.getKey(), entry.getValue()));
              writer.writeEndElement();
           }
        }
  
        writer.writeEndElement();
     }
docs: Store capacity
  @param e The extension
  @param writer The writer
  @param elementName the element name
  @exception XMLStreamException Thrown if an error occurs