Why the public method of the Android source code, will not be found in the official website and we can not use it?

Why the public method of the Android source code, will not be found in the official website and we can not use it?

For example, look at this:

on the Android developer Web Search is not found this method, we also can not call, why? This is because we can only call to the Android framework layer to provide us with the API, and this method framework layer is not open call, so naturally we will not be called. However, we can call such methods indirectly by reflection (see my previous blog for details).

See Android source code online URL: Http://grepcode.com/project/repository.grepcode.com/java/ext/com.google.android/android/