@Override
        public @NotNull Iterator<K> iterator() {
          return new MyIterator<K>() {
            @Override
            K fieldElement(int offset) {
              return offset == 0 ? k1 : offset == 1 ? k2 : k3;
            }

            @SuppressWarnings("unchecked")
            @Override
            K tableElement(int offset) {
              return (K)data[offset];
            }
          };
        }
@Override
        public @NotNull Iterator<K> iterator()