lines.add(line + end);
          }
        };
    char[] chars = input.toCharArray();
    int off = 0;
    while (off < chars.length) {
      int len = min(chars.length, off + chunk) - off;
      lineBuf.add(chars, off, len);
      off += len;
    }
    lineBuf.finish();
    return lines;
  }

  protected void update(byte[] b) {
    update(b, 0, b.length);
  }

  /** Updates this hasher with {@code len} bytes starting at {@code off} in the given buffer. */
  protected void update(byte[] b, int off, int len) {
    for (int i = off; i < off + len; i++) {
      update(b[i]);
    }
  }

  /** Updates this hasher with bytes from the given buffer. */
  protected void update(ByteBuffer b) {

    @CanIgnoreReturnValue
    @Override
    public Hasher putBytes(byte[] bytes, int off, int len) {
      checkPositionIndexes(off, off + len, bytes.length);
      int i;
      for (i = 0; i + 4 <= len; i += 4) {
        update(4, getIntLittleEndian(bytes, off + i));
      }
      for (; i < len; i++) {
        putByte(bytes[off + i]);
      }
      return this;
    }

    @CanIgnoreReturnValue

    checkNotNull(str);
    checkNotClosed();
    target.append(str);
  }

  @Override
  public void write(String str, int off, int len) throws IOException {
    checkNotNull(str);
    checkNotClosed();
    // tricky: append takes start, end pair...
    target.append(str, off, off + len);
  }

  @Override
  public void flush() throws IOException {
    checkNotClosed();
    if (target instanceof Flushable) {

      bufs.add(buf);
      int off = 0;
      while (off < buf.length) {
        // always OK to fill buf; its size plus the rest of bufs is never more than MAX_ARRAY_LEN
        int r = in.read(buf, off, buf.length - off);
        if (r == -1) {
          return combineBuffers(bufs, totalLen);
        }
        off += r;
        totalLen += r;
      }
    }

        super.write(c);
        flush();
      }

      @Override
      public void write(char[] cbuf, int off, int len) throws IOException {
        super.write(cbuf, off, len);
        flush();
      }

      @Override
      public void write(String str, int off, int len) throws IOException {
        super.write(str, off, len);
        flush();
      }
    };
  }

  /**
   * Puts a chunk of an array of bytes into this sink. {@code bytes[off]} is the first byte written,
   * {@code bytes[off + len - 1]} is the last.
   *
   * @param bytes a byte array
   * @param off the start offset in the array
   * @param len the number of bytes to write
   * @return this instance
   * @throws IndexOutOfBoundsException if {@code off < 0} or {@code off + len > bytes.length} or
   *     {@code len < 0}
   */

    @CanIgnoreReturnValue
    @Override
    public Hasher putBytes(byte[] bytes, int off, int len) {
      checkPositionIndexes(off, off + len, bytes.length);
      int i;
      for (i = 0; i + 4 <= len; i += 4) {
        update(4, getIntLittleEndian(bytes, off + i));
      }
      for (; i < len; i++) {
        putByte(bytes[off + i]);
      }
      return this;
    }

    @CanIgnoreReturnValue

    return putBytes(bytes, 0, bytes.length);
  }

  @Override
  @CanIgnoreReturnValue
  public Hasher putBytes(byte[] bytes, int off, int len) {
    Preconditions.checkPositionIndexes(off, off + len, bytes.length);
    for (int i = 0; i < len; i++) {
      putByte(bytes[off + i]);
    }
    return this;
  }

  @Override
  @CanIgnoreReturnValue
  public Hasher putBytes(ByteBuffer b) {
    if (b.hasArray()) {

    testThreshold(1000, 100, false, true);
  }

  static void write(OutputStream out, byte[] b, int off, int len, boolean singleByte)
      throws IOException {
    if (singleByte) {
      for (int i = off; i < off + len; i++) {
        out.write(b[i]);
      }
    } else {
      out.write(b, off, len);
    }
    out.flush(); // for coverage
  }