buffer[i] = (short) 0;
        }
    }

    @Override
    public String toString() {
        final int len = length / 2 - (zterm ? 1 : 0);
        final char[] ca = new char[len];
        for (int i = 0; i < len; i++) {
            ca[i] = (char) buffer[i];
        }
        return new String(ca, 0, len);
    }

            break;
        default:
            break;
        }
        return OptionalEntity.empty();
    }

    /**
     * Create a char mapping item.
     * @param form The create form.
     * @param hook The error hook.
     * @return An optional entity of a char mapping item.
     */
    protected OptionalEntity<CharMappingItem> createCharMappingItem(final CreateForm form, final VaErrorHook hook) {
        try {

     */
    public static char[] addAll(final char[] a, final char[] b) {
        if (a == null) {
            return b;
        }
        if (b == null) {
            return a;
        }
        if (a.length == 0) {
            return b;
        }
        if (b.length == 0) {
            return a;
        }
        final char[] array = (char[]) Array.newInstance(char.class, a.length + b.length);

   */
  AppendableWriter(Appendable target) {
    this.target = checkNotNull(target);
  }

  /*
   * Abstract methods from Writer
   */

  @Override
  public void write(char[] cbuf, int off, int len) throws IOException {
    checkNotClosed();
    // It turns out that creating a new String is usually as fast, or faster
    // than wrapping cbuf in a light-weight CharSequence.

    assertThat(expected).hasMessageThat().isEqualTo(msg);
  }

  public void testBadArguments_plusforspace() {
    // space can be a safe char if plusForSpace is false
    PercentEscaper unused = new PercentEscaper(" ", false);

    // space cannot be a safe char is plusForSpace is true
    String msg = "plusForSpace cannot be specified when space is a 'safe' character";
    IllegalArgumentException expected =

        assertEquals('N', (char) type2Bytes[0]);
        assertEquals('T', (char) type2Bytes[1]);
        assertEquals('L', (char) type2Bytes[2]);
        assertEquals('M', (char) type2Bytes[3]);
        assertEquals('S', (char) type2Bytes[4]);
        assertEquals('S', (char) type2Bytes[5]);
        assertEquals('P', (char) type2Bytes[6]);
        assertEquals(0, type2Bytes[7]); // Null terminator

        assertEquals(testStringTrue.length() + 1, unicodeStringTrue.buffer.length, "Buffer length should include zterm");
        for (int i = 0; i < testStringTrue.length(); i++) {
            assertEquals(testStringTrue.charAt(i), (char) unicodeStringTrue.buffer[i], "Character mismatch");
        }
        assertEquals(0, unicodeStringTrue.buffer[testStringTrue.length()], "Last character should be zero");

        // Test with a non-empty string and zterm = false

   * @param hi the high surrogate pair character
   * @param lo the low surrogate pair character
   */
  public static void assertUnicodeEscaping(
      UnicodeEscaper escaper, String expected, char hi, char lo) {

    int cp = Character.toCodePoint(hi, lo);
    String escaped = computeReplacement(escaper, cp);
    Assert.assertNotNull(escaped);
    Assert.assertEquals(expected, escaped);
  }

   * @param hi the high surrogate pair character
   * @param lo the low surrogate pair character
   */
  public static void assertUnicodeEscaping(
      UnicodeEscaper escaper, String expected, char hi, char lo) {

    int cp = Character.toCodePoint(hi, lo);
    String escaped = computeReplacement(escaper, cp);
    Assert.assertNotNull(escaped);
    Assert.assertEquals(expected, escaped);
  }

  }

  /**
   * Reads a char as specified by {@link DataInputStream#readChar()}, except using little-endian
   * byte order.
   *
   * @return the next two bytes of the input stream, interpreted as a {@code char} in little-endian
   *     byte order
   * @throws IOException if an I/O error occurs
   */
  @CanIgnoreReturnValue // to skip some bytes
  @Override
  public char readChar() throws IOException {