@Override
    public List<Character> create(Character[] elements) {
      char[] chars = Chars.toArray(asList(elements));
      return charactersOf(String.copyValueOf(chars));
    }
  }

  public static class CharactersOfCharSequenceGenerator extends TestCharacterListGenerator {
    @Override
    public List<Character> create(Character[] elements) {
      char[] chars = Chars.toArray(asList(elements));

    Set<Character> positive = Sets.newHashSetWithExpectedSize(chars.length);
    for (char c : chars) {
      positive.add(c);
    }
    for (int c = 0; c <= Character.MAX_VALUE; c++) {
      assertFalse(positive.contains(Character.valueOf((char) c)) ^ m.matches((char) c));
    }
  }

  static char[] randomChars(Random rand, int size) {
    Set<Character> chars = new HashSet<>(size);

    // Host names are special:
    //
    //  * Several characters are forbidden and must throw exceptions if used.
    //  * They don't use percent escaping at all.
    //  * They use punycode for internationalization.
    //  * URI is much more strict than HttpUrl or URL on what's accepted.
    //
    // HttpUrl is quite lenient with what characters it accepts. In particular, characters like '{'

  PRIVATE(':', ','),
  /** Public suffix that is backed by an ICANN-style domain name registry */
  REGISTRY('!', '?');

  /** The character used for an inner node in the trie encoding */
  private final char innerNodeCode;

  /** The character used for a leaf node in the trie encoding */
  private final char leafNodeCode;

  PublicSuffixType(char innerNodeCode, char leafNodeCode) {

    // Valid radix values are Character.MIN_RADIX to Character.MAX_RADIX, inclusive.
    assertThrows(
        NumberFormatException.class,
        () -> UnsignedLongs.parseUnsignedLong("0", Character.MIN_RADIX - 1));

    assertThrows(
        NumberFormatException.class,
        () -> UnsignedLongs.parseUnsignedLong("0", Character.MAX_RADIX + 1));

   *                  str -> str.substring(1).chars().mapToObj(c -> (char) c));
   *
   * // is equivalent to
   *
   * static final ImmutableListMultimap<Character, Character> FIRST_LETTER_MULTIMAP =
   *     ImmutableListMultimap.<Character, Character>builder()
   *         .putAll('b', Arrays.asList('a', 'n', 'a', 'n', 'a'))
   *         .putAll('a', Arrays.asList('p', 'p', 'l', 'e'))
   *         .putAll('c', Arrays.asList('a', 'r', 'r', 'o', 't'))

    super(false, false, false, false, false);
  }

  @Override
  Table<String, Character, Integer> makeTable() {
    RowSortedTable<String, Character, Integer> table = TreeBasedTable.create();
    return unmodifiableRowSortedTable(table);
  }

  @Override
  protected Map<String, Integer> makePopulatedMap() {
    RowSortedTable<String, Character, Integer> table = TreeBasedTable.create();
    table.put("one", 'a', 1);

    super(false, false, false, false, false);
  }

  @Override
  Table<String, Character, Integer> makeTable() {
    Table<String, Character, Integer> table = HashBasedTable.create();
    return unmodifiableTable(table);
  }

  @Override
  protected Map<String, Integer> makePopulatedMap() {
    Table<String, Character, Integer> table = HashBasedTable.create();
    table.put("one", 'a', 1);
    table.put("two", 'a', 2);

    super(false, false, true, true, true);
  }

  @Override
  Table<Character, String, Integer> makeTable() {
    Table<Character, String, Integer> table = HashBasedTable.create();
    return transformValues(table, TableCollectionTest.DIVIDE_BY_2);
  }

  @Override
  protected Map<String, Integer> makePopulatedMap() {
    Table<Character, String, Integer> table = HashBasedTable.create();
    table.put('a', "one", 2);

   */
  @VisibleForTesting
  static boolean validSurrogatePairAt(CharSequence string, int index) {
    return index >= 0
        && index <= (string.length() - 2)
        && Character.isHighSurrogate(string.charAt(index))
        && Character.isLowSurrogate(string.charAt(index + 1));
  }

  /**
   * Returns the given {@code template} string with each occurrence of {@code "%s"} replaced with