assertThat(joiner.appendTo(sb2, array)).isSameInstanceAs(sb2);
    assertEquals(0, sb2.length());

    try {
      joiner.appendTo(NASTY_APPENDABLE, set);
    } catch (IOException e) {
      throw new AssertionError(e);
    }

    try {
      joiner.appendTo(NASTY_APPENDABLE, set.iterator());
    } catch (IOException e) {
      throw new AssertionError(e);
    }

    try {

      @Override
      public Iterator<String> iterator() {
        return splittingIterator(sequence);
      }

      @Override
      public String toString() {
        return Joiner.on(", ")
            .appendTo(new StringBuilder().append('['), this)
            .append(']')
            .toString();
      }
    };
  }

  private Iterator<String> splittingIterator(CharSequence sequence) {

      @Override
      public Iterator<String> iterator() {
        return splittingIterator(sequence);
      }

      @Override
      public String toString() {
        return Joiner.on(", ")
            .appendTo(new StringBuilder().append('['), this)
            .append(']')
            .toString();
      }
    };
  }

  private Iterator<String> splittingIterator(CharSequence sequence) {