Object[] table = builder.hashTable;
    assertNotNull(table);
    assertSame(table, ((RegularImmutableSet<String>) builder.build()).table);
  }

  @GwtIncompatible // Builder impl
  public void testPresizedBuilderForceCopy() {
    for (int expectedSize = 1; expectedSize < 4; expectedSize++) {
      ImmutableSet.Builder<Integer> builder = ImmutableSet.builderWithExpectedSize(expectedSize);
      builder.add(-1);