public static bool Contains_ObjOfClass(this IEnumerable <UPortedItem_Info> input,
                                        UObjPurposeClass purpose_class)
 {
     foreach (var v in input)
     {
         if (v.Is(purpose_class))
         {
             return(true);
         }
     }
     return(false);
 }
        public bool Is(UObjPurposeClass purpose_class)
        {
            switch (purpose_class)
            {
            case UObjPurposeClass.Material:
                return(ObjClass.Equals(UObjectClass.MaterialInstanceConstant));

            case UObjPurposeClass.Mesh:
                return(ObjClass.Equals(UObjectClass.SkeletalMesh));

            case UObjPurposeClass.Texture:
                return(ObjClass.Equals(UObjectClass.Texture2D));

            default:
                throw new Exception("Coder's fault.");
            }
        }