code: private Object refObj(Object obj, Element node) throws Exception {
  		String id = getAttribute(node, "id");
  		//CHECKSTYLE:OFF
  		obj = _idMap.get(id);
  		//CHECKSTYLE:ON
  		if (obj == null) {
  			throw new IllegalStateException("No object for id=" + id);
  		}
  		configure(obj, node, 0);
  		return obj;
  	}
docs: /*
  Reference an id value object.
  
  @param obj @param node @return @exception NoSuchMethodException
  
  @exception ClassNotFoundException @exception InvocationTargetException