* the same sequence when read using each type of read method it provides.
   */
  private static void assertReadsCorrectly(CharSequence charSequence) throws IOException {
    String expected = charSequence.toString();

    // read char by char
    CharSequenceReader reader = new CharSequenceReader(charSequence);

  @Override
  @CanIgnoreReturnValue
  public Hasher putUnencodedChars(CharSequence charSequence) {
    for (int i = 0, len = charSequence.length(); i < len; i++) {
      putChar(charSequence.charAt(i));
    }
    return this;
  }

  @Override
  @CanIgnoreReturnValue
  public Hasher putString(CharSequence charSequence, Charset charset) {
    return putBytes(charSequence.toString().getBytes(charset));
  }

  @Override

    checkNotClosed();
    target.append(c);
    return this;
  }

  @Override
  public Writer append(@Nullable CharSequence charSeq) throws IOException {
    checkNotClosed();
    target.append(charSeq);
    return this;
  }

  @Override
  public Writer append(@Nullable CharSequence charSeq, int start, int end) throws IOException {
    checkNotClosed();
    target.append(charSeq, start, end);
    return this;

    // This benchmark has no concept of "noWorkToDo".
    String upperString = testString.toUpperCase();
    CharSequence testSeq = new StringBuilder(testString);
    CharSequence upperSeq = new StringBuilder(upperString);
    CharSequence[] lhs = new CharSequence[] {testString, testSeq, testString, testSeq};
    CharSequence[] rhs = new CharSequence[] {upperString, upperString, upperSeq, upperSeq};

    boolean dummy = false;

    return this;
  }

  /*
   * Note: hashString(CharSequence, Charset) is intentionally not overridden.
   *
   * While intuitively, using CharsetEncoder to encode the CharSequence directly to the buffer (or
   * even to an intermediate buffer) should be considerably more efficient than potentially
   * copying the CharSequence to a String and then calling getBytes(Charset) on that String, in

 *   protected Object handleInvocation(Object proxy, Method method, Object[] args) {
 *     throw new UnsupportedOperationException();
 *   }
 * }
 *
 * CharSequence unsupported = Reflection.newProxy(CharSequence.class, new Unsupported());
 * </pre>
 *
 * @author Ben Yu
 * @since 12.0
 */
public abstract class AbstractInvocationHandler implements InvocationHandler {

   * putUnencodedChars}.
   *
   * @since 15.0 (since 11.0 as putString(CharSequence)).
   */
  @CanIgnoreReturnValue
  @Override
  Hasher putUnencodedChars(CharSequence charSequence);

  /**
   * Equivalent to {@code putBytes(charSequence.toString().getBytes(charset))}.
   *
   * <p><b>Warning:</b> This method, which reencodes the input before hashing it, is useful only for

    // This benchmark has no concept of "noWorkToDo".
    String upperString = testString.toUpperCase();
    CharSequence testSeq = new StringBuilder(testString);
    CharSequence upperSeq = new StringBuilder(upperString);
    CharSequence[] lhs = new CharSequence[] {testString, testSeq, testString, testSeq};
    CharSequence[] rhs = new CharSequence[] {upperString, upperString, upperSeq, upperSeq};

    boolean dummy = false;

   *
   * @throws IOException if an I/O error while writing to this sink
   */
  public void write(CharSequence charSequence) throws IOException {
    checkNotNull(charSequence);

    try (Writer out = openStream()) {
      out.append(charSequence);
    }
  }

  /**
   * Writes the given lines of text to this sink with each line (including the last) terminated with

   * 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.