builder.add(Range.singleton(i));
      }
      return builder.build().asSet(DiscreteDomain.integers());
    }
  }

  @AndroidIncompatible // test-suite builders
  static final class ImmutableRangeSetBigIntegerAsSetGenerator
      implements TestSetGenerator<BigInteger> {
    @Override
    public SampleElements<BigInteger> samples() {
      return new SampleElements<>(
          BigInteger.valueOf(1),