How does the Geocoder class in android work?

I wanted to peek in the Geocoder class in android to understand how it works. But when I opened it in the ide I found this class had nothing much but only few methods which only created some RuntimeException objects. So how does it work. What pattern is it using ?

this the class which I got when the .class file was Decompiled by the ide.

public final class Geocoder {
        public Geocoder(Context context, Locale locale) {
         throw new RuntimeException("Stub!");
        }

        public Geocoder(Context context) {
         throw new RuntimeException("Stub!");
        }

        public static boolean isPresent() {
         throw new RuntimeException("Stub!");
        }

public List<Address> getFromLocation(double latitude, double longitude, 
  int maxResults) throws IOException {
    throw new RuntimeException("Stub!");
}

public List<Address> getFromLocationName(String locationName, int maxResults) throws IOException {
    throw new RuntimeException("Stub!");
}

public List<Address> getFromLocationName(String locationName, int maxResults, double lowerLeftLatitude, double lowerLeftLongitude, double upperRightLatitude, double upperRightLongitude) throws IOException {
    throw new RuntimeException("Stub!");
}
}

any help will be appreciated.