RegularImmutableSet<String> set = (RegularImmutableSet<String>) builder.build();
    builder.add("baz");
    assertTrue(set.elements != builder.contents);
  }

  public void testReuseBuilderReducingHashTableSizeWithPowerOfTwoTotalElements() {
    ImmutableSet.Builder<Object> builder = ImmutableSet.builderWithExpectedSize(6);
    builder.add(0);
    ImmutableSet<Object> unused = builder.build();