// Start with "%--" and fill in the blanks
      char[] dest = new char[3];
      dest[0] = '%';
      dest[2] = upperHexDigits[cp & 0xF];
      dest[1] = upperHexDigits[cp >>> 4];
      return dest;
    } else if (cp <= 0x7ff) {
      // Two byte UTF-8 characters [cp >= 0x80 && cp <= 0x7ff]
      // Start with "%--%--" and fill in the blanks
      char[] dest = new char[6];
      dest[0] = '%';
      dest[3] = '%';

class MultipartReaderTest {
  @Test fun `parse multipart`() {
    val multipart =
      """
      |--simple boundary
      |Content-Type: text/plain; charset=utf-8
      |Content-ID: abc
      |
      |abcd
      |efgh
      |--simple boundary
      |Content-Type: text/plain; charset=utf-8
      |Content-ID: ijk
      |
      |ijkl
      |mnop
      |
      |--simple boundary--
      """.trimMargin()

    int utf8Length = utf16Length;
    int i = 0;

    // This loop optimizes for pure ASCII.
    while (i < utf16Length && sequence.charAt(i) < 0x80) {
      i++;
    }

    // This loop optimizes for chars less than 0x800.
    for (; i < utf16Length; i++) {
      char c = sequence.charAt(i);
      if (c < 0x800) {
        utf8Length += (0x7f - c) >>> 31; // branch free!
      } else {

    String testString = "abcdef";
    Reader reader = new StringReader(testString);

    assertEquals(testString.charAt(0), reader.read());
    CharStreams.skipFully(reader, 1);
    assertEquals(testString.charAt(2), reader.read());
    CharStreams.skipFully(reader, 2);
    assertEquals(testString.charAt(5), reader.read());

    assertEquals(-1, reader.read());
  }

  public void testAsWriter() {

    String testString = "abcdef";
    Reader reader = new StringReader(testString);

    assertEquals(testString.charAt(0), reader.read());
    CharStreams.skipFully(reader, 1);
    assertEquals(testString.charAt(2), reader.read());
    CharStreams.skipFully(reader, 2);
    assertEquals(testString.charAt(5), reader.read());

    assertEquals(-1, reader.read());
  }

  public void testAsWriter() {

   * charset} parameter set to the {@link Charset#name name} of the given charset. Only one {@code
   * charset} parameter will be present on the new instance regardless of the number set on this
   * one.
   *
   * <p>If a charset must be specified that is not supported on this JVM (and thus is not
   * representable as a {@link Charset} instance), use {@link #withParameter}.
   */

      imports = "com.google.common.io.Files")
  public
  static void copy(File from, Charset charset, Appendable to) throws IOException {
    asCharSource(from, charset).copyTo(to);
  }

  /**
   * Appends a character sequence (such as a string) to a file using the given character set.
   *
   * @param from the character sequence to append
   * @param to the destination file

   * charset} parameter set to the {@link Charset#name name} of the given charset. Only one {@code
   * charset} parameter will be present on the new instance regardless of the number set on this
   * one.
   *
   * <p>If a charset must be specified that is not supported on this JVM (and thus is not
   * representable as a {@link Charset} instance), use {@link #withParameter}.
   */

   */
  private static char[] growBuffer(char[] dest, int index, int size) {
    if (size < 0) { // overflow - should be OutOfMemoryError but GWT/j2cl don't support it
      throw new AssertionError("Cannot increase internal buffer any further");
    }
    char[] copy = new char[size];
    if (index > 0) {
      System.arraycopy(dest, 0, copy, 0, index);
    }

   */
  private static char[] growBuffer(char[] dest, int index, int size) {
    if (size < 0) { // overflow - should be OutOfMemoryError but GWT/j2cl don't support it
      throw new AssertionError("Cannot increase internal buffer any further");
    }
    char[] copy = new char[size];
    if (index > 0) {
      System.arraycopy(dest, 0, copy, 0, index);
    }