code: public List<String> attrNames() {
  		String[] names = this._getAttrNames();
  		if (null != names && names.length != 0) {
  			return Arrays.asList(names);
  		}
  		Method[] methods = this._getUsefulClass().getMethods();
  		String methodName;
  		List<String> attrs = new ArrayList<String>();
  		for (Method method : methods) {
  			methodName = method.getName();
  			if (methodName.startsWith("set") ) {
  				String attr = methodName.substring(3).toLowerCase();
  				if (StrKit.notBlank(attr)) {
  					attrs.add(attr);
  				}
  			}
  		}
  		return attrs;
  	}
docs: Get attr names