docs: public String processIndexDescriptor(Properties attributes) throws XDocletException
      {
          String             name     = attributes.getProperty(ATTRIBUTE_NAME);
          IndexDescriptorDef indexDef = _curClassDef.getIndexDescriptor(name);
          String             attrName;
          
          if (indexDef == null)
          {    
              indexDef = new IndexDescriptorDef(name);
              _curClassDef.addIndexDescriptor(indexDef);
          }
  
          if ((indexDef.getName() == null) || (indexDef.getName().length() == 0))
          {
              throw new XDocletException(Translator.getString(XDocletModulesOjbMessages.class,
                                         XDocletModulesOjbMessages.INDEX_NAME_MISSING,
                                         new String[]{_curClassDef.getName()}));
          }
          attributes.remove(ATTRIBUTE_NAME);
          for (Enumeration attrNames = attributes.propertyNames(); attrNames.hasMoreElements(); )
          {
              attrName = (String)attrNames.nextElement();
              indexDef.setProperty(attrName, attributes.getProperty(attrName));
          }
          return "";
      }