Ayatana indicators ! Dev Guid ? Help!

Where can I find indepth guide on developing indicators ?
I only have found the API . I browsed the src of compiz-indicator and found
icon = appindicator.Indicator(‘compiz-indicator’, ‘fusion-icon’, appindicator.CATEGORY_APPLICATION_STATUS),
so the Indicator function witch is in the class appindicator is not presented in the API documentation .
I can only guess wath the parameters are . “compiz-indicator” should be the name of the indicator
“fusion-icon” should be the icon .