String doubled = "a,, b,c";
    Iterable<String> letters = COMMA_SPLITTER.split(doubled);
    assertThat(letters).containsExactly("a", "", " b", "c").inOrder();
  }

  public void testCharacterSplitWithTrailingDelimiter() {
    String trailing = "a,b,c,";
    Iterable<String> letters = COMMA_SPLITTER.split(trailing);
    assertThat(letters).containsExactly("a", "b", "c", "").inOrder();
  }