* time and space.
   *
   * @throws IllegalArgumentException if {@code sequence} contains ill-formed UTF-16 (unpaired
   *     surrogates)
   */
  public static int encodedLength(CharSequence sequence) {
    // Warning to maintainers: this implementation is highly optimized.
    int utf16Length = sequence.length();
    int utf8Length = utf16Length;
    int i = 0;

    // This loop optimizes for pure ASCII.

   * characters which constitute a machine-sensible address or routing information. Such a sequence
   * is referred to as the "heading." An STX character has the effect of terminating a heading.
   *
   * @since 8.0
   */
  public static final byte SOH = 1;

  /**
   * Start of Text: A communication control character which precedes a sequence of characters that

   * sequence. Returns a bogus matcher if the sequence contains supplementary characters.
   */
  public static CharMatcher anyOf(final CharSequence sequence) {
    switch (sequence.length()) {
      case 0:
        return none();
      case 1:
        return is(sequence.charAt(0));
      case 2:
        return isEither(sequence.charAt(0), sequence.charAt(1));
      default:

   * time and space.
   *
   * @throws IllegalArgumentException if {@code sequence} contains ill-formed UTF-16 (unpaired
   *     surrogates)
   */
  public static int encodedLength(CharSequence sequence) {
    // Warning to maintainers: this implementation is highly optimized.
    int utf16Length = sequence.length();
    int utf8Length = utf16Length;
    int i = 0;

    // This loop optimizes for pure ASCII.

   * sequence. Returns a bogus matcher if the sequence contains supplementary characters.
   */
  public static CharMatcher anyOf(final CharSequence sequence) {
    switch (sequence.length()) {
      case 0:
        return none();
      case 1:
        return is(sequence.charAt(0));
      case 2:
        return isEither(sequence.charAt(0), sequence.charAt(1));
      default:

   * {@code sequence} as a sequence of Unicode code units. The view does not support any
   * modification operations, but reflects any changes to the underlying character sequence.
   *
   * @param sequence the character sequence to view as a {@code List} of characters
   * @return an {@code List<Character>} view of the character sequence
   * @since 7.0
   */

  /** Returns the element with the specified index. This method is called by {@link #next()}. */
  @ParametricNullness
  protected abstract E get(int index);

  /**
   * Constructs an iterator across a sequence of the given size whose initial position is 0. That
   * is, the first call to {@link #next()} will return the first element (or throw {@link
   * NoSuchElementException} if {@code size} is zero).
   *

  }

  private Iterator<String> splittingIterator(CharSequence sequence) {
    return strategy.iterator(this, sequence);
  }

  /**
   * Splits {@code sequence} into string components and returns them as an immutable list. If you
   * want an {@link Iterable} which may be lazily evaluated, use {@link #split(CharSequence)}.
   *
   * @param sequence the sequence of characters to split

  }

  private Iterator<String> splittingIterator(CharSequence sequence) {
    return strategy.iterator(this, sequence);
  }

  /**
   * Splits {@code sequence} into string components and returns them as an immutable list. If you
   * want an {@link Iterable} which may be lazily evaluated, use {@link #split(CharSequence)}.
   *
   * @param sequence the sequence of characters to split

 * good" reference implementation. In order to accomplish this, it's important to test a great
 * variety of sequences of the {@link Iterator#next}, {@link Iterator#hasNext} and {@link
 * Iterator#remove} operations. This utility takes the brute-force approach of trying <i>all</i>
 * possible sequences of these operations, up to a given number of steps. So, if the caller