public void popScene()
{
NSUtils.Assert( _runningScene != null, "A running Scene is needed");
_scenesStack.Pop();
int c = _scenesStack.Count;
if( c == 0 )
this.end();
else {
_sendCleanupToScene = true;
_nextScene = _scenesStack.Peek();
_runningScene.gameObject.SetActive(_runningScene.visible);
}
}