/**
  * When using Play Game Services with a standard Java Activity, JNI_OnLoad
  * should be called when the dynamic library's JNI_OnLoad is called.
  */
 static void JNI_OnLoad(JavaVM *jvm);

 /**
  * When using Play Game Services with a NativeActivity which is based on
  * android_native_app_glue.h, android_main should be called during your
  * activity's android_main, before any other Play Game Services calls.
  */
 static void android_main(struct android_app *app);

 /**
  * When using Play Game Services with a NativeActivity which is based on only
  * native_activity.h, ANativeActivity_onCreate should be called during your
  * activity's ANativeActivity_onCreate, before any other Play Game Services
  * calls.
  */
 static void ANativeActivity_onCreate(ANativeActivity *native_activity,
                                      void *savedState,
                                      size_t savedStateSize);