return false;
    }

    Alphabet upperCase() {
      if (!hasLowerCase()) {
        return this;
      }
      checkState(!hasUpperCase(), "Cannot call upperCase() on a mixed-case alphabet");
      char[] upperCased = new char[chars.length];
      for (int i = 0; i < chars.length; i++) {
        upperCased[i] = Ascii.toUpperCase(chars[i]);
      }
      Alphabet upperCase = new Alphabet(name + ".upperCase()", upperCased);

    assertFailsToDecode(base64(), "?", "Invalid input length 1");
  }

  public void testBase64CannotUpperCase() {
    assertThrows(IllegalStateException.class, () -> base64().upperCase());
  }

  public void testBase64CannotLowerCase() {
    assertThrows(IllegalStateException.class, () -> base64().lowerCase());
  }

  public void testBase64CannotIgnoreCase() {

  /** A bit mask which selects the bit encoding ASCII character case. */
  private static final char CASE_MASK = 0x20;

  /**
   * Returns a copy of the input string in which all {@linkplain #isUpperCase(char) uppercase ASCII
   * characters} have been converted to lowercase. All other characters are copied without
   * modification.
   */
  public static String toLowerCase(String string) {
    int length = string.length();

   *       byte is then represented by the 3-character string "%XY", where "XY" is the two-digit,
   *       uppercase, hexadecimal representation of the byte value.
   * </ul>
   *
   * <p><b>Note:</b> Unlike other escapers, URL escapers produce <a
   * href="https://url.spec.whatwg.org/#percent-encode">uppercase</a> hexadecimal sequences.
   */
  public static Escaper urlPathSegmentEscaper() {
    return URL_PATH_SEGMENT_ESCAPER;

        original!!.writeTo(bufferedSink)
        bufferedSink.emit()
      }
    }
  }

  private fun uppercase(original: BufferedSink): Sink {
    return object : ForwardingSink(original) {
      override fun write(
        source: Buffer,
        byteCount: Long,
      ) {
        original.writeUtf8(source.readUtf8(byteCount).uppercase())
      }
    }
  }

   *       byte is then represented by the 3-character string "%XY", where "XY" is the two-digit,
   *       uppercase, hexadecimal representation of the byte value.
   * </ul>
   *
   * <p><b>Note:</b> Unlike other escapers, URL escapers produce <a
   * href="https://url.spec.whatwg.org/#percent-encode">uppercase</a> hexadecimal sequences.
   */
  public static Escaper urlPathSegmentEscaper() {
    return URL_PATH_SEGMENT_ESCAPER;

import okio.buffer

/** Rewrites the request body sent to the server to be all uppercase.  */
class UppercaseRequestInterceptor : Interceptor {
  @Throws(IOException::class)
  override fun intercept(chain: Chain): Response {
    return chain.proceed(uppercaseRequest(chain.request()))
  }

  /** Returns a request that transforms `request` to be all uppercase.  */
  private fun uppercaseRequest(request: Request): Request {

            ).joinToString(separator = " ")
        steps {
            gradleWrapper {
                name = "FLAKY_TEST_QUARANTINE_${testCoverage.testType.name.uppercase()}_${testCoverage.testJvmVersion.name.uppercase()}"
                val testTaskName =
                    if (testCoverage.testType == TestType.isolatedProjects) "isolatedProjectsIntegTest" else "${testCoverage.testType.name}Test"

    assertFailsToDecode(base64(), "?", "Invalid input length 1");
  }

  public void testBase64CannotUpperCase() {
    assertThrows(IllegalStateException.class, () -> base64().upperCase());
  }

  public void testBase64CannotLowerCase() {
    assertThrows(IllegalStateException.class, () -> base64().lowerCase());
  }

  public void testBase64CannotIgnoreCase() {

  /** A bit mask which selects the bit encoding ASCII character case. */
  private static final char CASE_MASK = 0x20;

  /**
   * Returns a copy of the input string in which all {@linkplain #isUpperCase(char) uppercase ASCII
   * characters} have been converted to lowercase. All other characters are copied without
   * modification.
   */
  public static String toLowerCase(String string) {
    int length = string.length();