* UnsupportedOperationException.
   *
   * <p>The implementation deviates from the {@code ExecutorService} specification with regards to
   * the {@code shutdownNow} method. First, "best-effort" with regards to canceling running tasks is
   * implemented as "no-effort". No interrupts or other attempts are made to stop threads executing
   * tasks. Second, the returned list will always be empty, as any submitted task is considered to

   * UnsupportedOperationException.
   *
   * <p>The implementation deviates from the {@code ExecutorService} specification with regards to
   * the {@code shutdownNow} method. First, "best-effort" with regards to canceling running tasks is
   * implemented as "no-effort". No interrupts or other attempts are made to stop threads executing
   * tasks. Second, the returned list will always be empty, as any submitted task is considered to

    message: String,
    stackTrace: Any?,
  ) {
    if (Build.VERSION.SDK_INT >= 30) {
      (stackTrace as CloseGuard).warnIfOpen()
    } else {
      // Unable to report via CloseGuard. As a last-ditch effort, send it to the logger.
      super.logCloseableLeak(message, stackTrace)
    }
  }

  @SuppressLint("NewApi")
  override fun isCleartextTrafficPermitted(hostname: String): Boolean =

   * Returns the given {@code template} string with each occurrence of {@code "%s"} replaced with
   * the corresponding argument value from {@code args}; or, if the placeholder and argument counts
   * do not match, returns a best-effort form of that string. Will not throw an exception under
   * normal conditions.
   *
   * <p><b>Note:</b> For most string-formatting needs, use {@link String#format String.format},

   * structure (to make it possible to throw ConcurrentModificationException in the iterator). Note
   * that we choose not to make this volatile, so we do less of a "best effort" to track such
   * errors, for better performance.
   */
  private transient int metadata;

  /** The number of elements contained in the set. */
  private transient int size;

    obvious way to ensure that.

    We could consider arranging things so that only the tests we know need this would get
    the add-opens. Right now that doesn't seem worth the effort, though.
    -->
    <test.add.opens>
      --add-opens java.base/java.lang=ALL-UNNAMED
      --add-opens java.base/java.util=ALL-UNNAMED
      --add-opens java.base/sun.security.jca=ALL-UNNAMED
    </test.add.opens>

    obvious way to ensure that.

    We could consider arranging things so that only the tests we know need this would get
    the add-opens. Right now that doesn't seem worth the effort, though.
    -->
    <test.add.opens>
      --add-opens java.base/java.lang=ALL-UNNAMED
      --add-opens java.base/java.util=ALL-UNNAMED
      --add-opens java.base/sun.security.jca=ALL-UNNAMED
    </test.add.opens>

   * structure (to make it possible to throw ConcurrentModificationException in the iterator). Note
   * that we choose not to make this volatile, so we do less of a "best effort" to track such
   * errors, for better performance.
   *
   * <p>For a new instance, where the arrays above have not yet been allocated, the value of {@code

  }

  public void testPrecomputedOptimizations() {
    // These are testing behavior that's never promised by the API.
    // Some matchers are so efficient that it is a waste of effort to
    // build a precomputed version.
    CharMatcher m1 = is('x');
    assertSame(m1, m1.precomputed());
    assertEquals(m1.toString(), m1.precomputed().toString());

    CharMatcher m2 = anyOf("Az");

 *
 * <p>The tested methods and constructors are invoked -- each time with one parameter being null and
 * the rest not null -- and the test fails if no expected exception is thrown. {@code
 * NullPointerTester} uses best effort to pick non-null default values for many common JDK and Guava
 * types, and also for interfaces and public classes that have public parameter-less constructors.