assertNotSame(builder.contents, prevArray);
      prevArray = builder.contents;
      ImmutableList<Integer> unused = builder.build();
    }
  }

  @GwtIncompatible
  public void testBuilderExactlySizedReusesArray() {
    ImmutableList.Builder<Integer> builder = ImmutableList.builderWithExpectedSize(10);
    Object[] builderArray = builder.contents;
    for (int i = 0; i < 10; i++) {
      builder.add(i);
    }