* {@link #hashString}, usually with a charset of UTF-8. For other use cases, use {@code
   * hashUnencodedChars}.
   *
   * @since 15.0 (since 11.0 as hashString(CharSequence)).
   */
  HashCode hashUnencodedChars(CharSequence input);

  /**
   * Shortcut for {@code newHasher().putString(input, charset).hash()}. Characters are encoded using

    }
    if (cp >= safeMin && cp <= safeMax) {
      return null;
    }
    return escapeUnsafe(cp);
  }

  /* Overridden for performance. */
  @Override
  protected final int nextEscapeIndex(CharSequence csq, int index, int end) {
    while (index < end) {
      char c = csq.charAt(index);
      if ((c < replacementsLength && replacements[c] != null)
          || c > safeMaxChar
          || c < safeMinChar) {

   * surprising behavior of {@code toUpperCase()} and {@code toLowerCase()}.
   *
   * @since 16.0
   */
  public static boolean equalsIgnoreCase(CharSequence s1, CharSequence s2) {
    // Calling length() is the null pointer check (so do it before we can exit early).
    int length = s1.length();
    if (s1 == s2) {
      return true;
    }
    if (length != s2.length()) {

   * 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.

    return new Appendable() {

      @Override
      public Appendable append(CharSequence csq) throws IOException {
        a.append(csq);
        return this;
      }

      @Override
      public Appendable append(CharSequence csq, int start, int end) throws IOException {
        a.append(csq, start, end);
        return this;
      }

      @Override

    return new Appendable() {

      @Override
      public Appendable append(CharSequence csq) throws IOException {
        a.append(csq);
        return this;
      }

      @Override
      public Appendable append(CharSequence csq, int start, int end) throws IOException {
        a.append(csq, start, end);
        return this;
      }

      @Override

    <T> void withoutBound(List<T> list) {}

    @SuppressWarnings("unused")
    <T extends Object> void withObjectBound(List<T> list) {}

    @SuppressWarnings("unused")
    <T extends Number & CharSequence> void withUpperBound(List<T> list) {}

    static TypeVariable<?> getTypeVariable(String methodName) throws Exception {
      ParameterizedType parameterType =
          (ParameterizedType)

              @Override
              public Sub apply(Sub sub) {
                return new ForwardingSub(sub);
              }
            });
  }

  interface Base {
    CharSequence getId();
  }

  interface Sub extends Base {
    @Override
    String getId();
  }

  private static class ForwardingSub implements Sub {
    private final Sub delegate;

    <T> void withoutBound(List<T> list) {}

    @SuppressWarnings("unused")
    <T extends Object> void withObjectBound(List<T> list) {}

    @SuppressWarnings("unused")
    <T extends Number & CharSequence> void withUpperBound(List<T> list) {}

    static TypeVariable<?> getTypeVariable(String methodName) throws Exception {
      ParameterizedType parameterType =
          (ParameterizedType)

      checkPositionIndexes(off, off + len, str.length());
    }

    @Override
    public Writer append(@CheckForNull CharSequence csq) {
      return this;
    }

    @Override
    public Writer append(@CheckForNull CharSequence csq, int start, int end) {
      checkPositionIndexes(start, end, csq == null ? "null".length() : csq.length());
      return this;
    }

    @Override