/**
  * Make the device lock immediately, as if the lock screen timeout has expired at the point of
  * this call.
  *
  * <p>The calling device admin must have requested {@link DeviceAdminInfo#USES_POLICY_FORCE_LOCK}
  * to be able to call this method; if it has not, a security exception will be thrown.
  */
 public void lockNow() {
   if (mService != null) {
     try {
       mService.lockNow();
     } catch (RemoteException e) {
       Log.w(TAG, "Failed talking with device policy service", e);
     }
   }
 }