buffer |= charToTwoUtf8Bytes(c) << shift;
          shift += 16;
          len += 2;
        } else if (c < Character.MIN_SURROGATE || c > Character.MAX_SURROGATE) {
          buffer |= charToThreeUtf8Bytes(c) << shift;
          shift += 24;
          len += 3;
        } else {
          int codePoint = Character.codePointAt(input, i);
          if (codePoint == c) {

    assertFailsToDecode(base16(), "\n\n", "Unrecognized character: 0xa");
    assertFailsToDecode(base16(), "EFGH", "Unrecognized character: G");
    // Valid base16 strings always have an even length.
    assertFailsToDecode(base16(), "A", "Invalid input length 1");
    assertFailsToDecode(base16(), "ABC");
    // These have a combination of invalid length and unrecognized characters.

            assertThrows(IllegalArgumentException.class, () -> new UUID(invalidUuid),
                    "Should throw IllegalArgumentException for invalid character in UUID string");
        }

        @Test
        @DisplayName("Constructor with UUID string containing non-hex character should throw IllegalArgumentException")
        void testConstructorWithStringNonHexCharacter() {
            // Arrange

            char character = version.charAt(i);
            int c = character;
            if (Character.isHighSurrogate(character)) {
                // read the next character as a low surrogate and combine into a single int
                try {
                    char low = version.charAt(i + 1);
                    char[] both = {character, low};
                    c = Character.codePointAt(both, 0);

 *
 * Percent encoding replaces a character (like `\ud83c\udf69`) with its UTF-8 hex bytes (like
 * `%F0%9F%8D%A9`). This approach works for whitespace characters, control characters, non-ASCII
 * characters, and characters that already have another meaning in a particular context.
 *
 * Percent encoding is used in every URL component except for the hostname. But the set of

          buffer |= charToTwoUtf8Bytes(c) << shift;
          shift += 16;
          len += 2;
        } else if (c < Character.MIN_SURROGATE || c > Character.MAX_SURROGATE) {
          buffer |= charToThreeUtf8Bytes(c) << shift;
          shift += 24;
          len += 3;
        } else {
          int codePoint = Character.codePointAt(input, i);
          if (codePoint == c) {

    val c = this[i]
    // The WHATWG Host parsing rules accepts some character codes which are invalid by
    // definition for OkHttp's host header checks (and the WHATWG Host syntax definition). Here
    // we rule out characters that would cause problems in host headers.
    if (c <= '\u001f' || c >= '\u007f') {
      return true
    }
    // Check for the characters mentioned in the WHATWG Host parsing spec:

}

/**
 * Returns the next index in this at or after [startIndex] that is a character from
 * [characters]. Returns the input length if none of the requested characters can be found.
 */
private fun String.indexOfElement(
  characters: String,
  startIndex: Int = 0,
): Int {
  for (i in startIndex until length) {
    if (this[i] in characters) {
      return i
    }
  }
  return length

            throw new SmbException("Path contains null bytes");
        }

        // Check for control characters
        if (strictMode && CONTROL_CHARS.matcher(path).find()) {
            log.warn("Path contains control characters: {}", sanitizeForLog(path));
            throw new SmbException("Path contains control characters");
        }

        // Check for traversal sequences
        if (containsTraversal(path)) {

    }

    @ParameterizedTest
    @DisplayName("Test invalid usernames")
    @ValueSource(strings = { "user name", // space
            "user#name", // invalid character
            "user$name" // invalid character
    })
    void testInvalidUsernames(String username) {
        assertThrows(IllegalArgumentException.class, () -> InputValidator.validateUsername(username));
    }

    @Test