@Override
    protected Set<E> delegate() {
      ImmutableSet.Builder<E> builder = ImmutableSet.builder();

      for (int i = 0; i < vector.length; i++) {
        long word = vector[i];
        int wordOrdinal = i * BITS_PER_WORD;
        for (int bitIndex = 0; bitIndex < BITS_PER_WORD; bitIndex++) {
          if (((word >>> bitIndex) & 1) != 0) {
            builder.add(domain.get(wordOrdinal + bitIndex));
          }
        }
      }

      return builder.build();
    }
Will throw an exception and leave the collection unmodified.
@throws UnsupportedOperationException always
@deprecated Modification operation are not supported.
ordinal/src/org/immutables/ordinal/ImmutableOrdinalSet.java