docs: public String processProcedureArgument(Properties attributes) throws XDocletException
      {
          String               id     = attributes.getProperty(ATTRIBUTE_NAME);
          ProcedureArgumentDef argDef = _curClassDef.getProcedureArgument(id);
          String               attrName;
          
          if (argDef == null)
          {    
              argDef = new ProcedureArgumentDef(id);
              _curClassDef.addProcedureArgument(argDef);
          }
  
          attributes.remove(ATTRIBUTE_NAME);
          for (Enumeration attrNames = attributes.propertyNames(); attrNames.hasMoreElements(); )
          {
              attrName = (String)attrNames.nextElement();
              argDef.setProperty(attrName, attributes.getProperty(attrName));
          }
          return "";
      }