*/
  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);
    }

      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

                continue;
            }

            char ch = s.charAt(pos);
            pos++;
            if (ch == '\\') {
                sb.append(ch);
                if (pos >= end) {
                    break; // ERROR, or let it go?
                }
                ch = s.charAt(pos);
                pos++;
            }

            sb.append(ch);
        }

   *     Stream.of("banana", "apple", "carrot", "asparagus", "cherry")
   *         .collect(
   *             flatteningToImmutableListMultimap(
   *                  str -> str.charAt(0),
   *                  str -> str.substring(1).chars().mapToObj(c -> (char) c));
   *
   * // is equivalent to
   *
   * static final ImmutableListMultimap<Character, Character> FIRST_LETTER_MULTIMAP =

    if (stringValue.length() == 0) {
      throw new NumberFormatException("empty string");
    }

    // Handle radix specifier if present
    String rawValue;
    int radix;
    char firstChar = stringValue.charAt(0);
    if (stringValue.startsWith("0x") || stringValue.startsWith("0X")) {
      rawValue = stringValue.substring(2);
      radix = 16;
    } else if (firstChar == '#') {

        // Test various complex field names
        String[] fieldNames = { "simple_field", "field-with-dashes", "field.with.dots", "field_with_underscores", "fieldWithCamelCase",
                "field with spaces", "field@with#special!chars", "フィールド名", "字段名称", "필드명" };

        for (String fieldName : fieldNames) {
            String encoded = BaseEncoding.base64().encode(fieldName.getBytes(StandardCharsets.UTF_8));

    String expected = "abcdabcd";

    // read the first 8 chars manually, since there's no equivalent to ByteSource.slice
    // TODO(cgdecker): Add CharSource.slice?
    StringBuilder builder = new StringBuilder();
    Reader reader = concatenated.openStream(); // no need to worry about closing
    for (int i = 0; i < 8; i++) {
      builder.append((char) reader.read());
    }
    assertEquals(expected, builder.toString());

        .isEqualTo(1);
    assertThat(
            Chars.indexOf(
                new char[] {(char) 2, (char) 3, (char) 2, (char) 3, (char) 4, (char) 2, (char) 3},
                new char[] {(char) 2, (char) 3, (char) 4}))
        .isEqualTo(2);
    assertThat(
            Chars.indexOf(
                new char[] {(char) 2, (char) 2, (char) 3, (char) 4, (char) 2, (char) 3, (char) 4},

      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