Accessibility Services provide us a way to take actions for users,Is it possible to shutdown a phone with this feature?As shown in the code :
public class MyAccessibilityService extends AccessibilityService {
@Override
public void onAccessibilityEvent(AccessibilityEvent event) {
    // get the source node of the event
    AccessibilityNodeInfo nodeInfo = event.getSource();
    // Use the event and node information to determine
    // what action to take
    // take action on behalf of the user
    nodeInfo.performAction(AccessibilityNodeInfo.ACTION_SCROLL_FORWARD);
    // recycle the nodeInfo object
    nodeInfo.recycle();
}
...
}
Can we implement 'shutdown' in "//what action to take" section? You can check this service in https://developer.android.com/guide/topics/ui/accessibility/services.html#act-for-users