public static NRTrackableAccessor Create(NRTrackableBehaviour target)
 {
     if (target is NRTrackableImageBehaviour)
     {
         return(new NRImageTargetAccessor((NRTrackableImageBehaviour)target));
     }
     Debug.LogError(target.GetType().ToString() + "is not derived from NRTrackableImageBehaviour");
     return(null);
 }