// 0 bytes
                Arguments.of(0L, null, "0 B"),
                Arguments.of(0L, ScaleUnit.BYTE, "0 B"),
                Arguments.of(0L, ScaleUnit.KILOBYTE, "0 kB"),
                Arguments.of(0L, ScaleUnit.MEGABYTE, "0 MB"),
                Arguments.of(0L, ScaleUnit.GIGABYTE, "0 GB"),

                // 5 bytes
                Arguments.of(5L, null, "5 B"),
                Arguments.of(5L, ScaleUnit.BYTE, "5 B"),

    ms.add("b");
    ms.add(null);
    ms.add("a");
    ms.add("b");
    ms.add(null, 2);

    assertThat(ms).containsExactly(null, null, null, "a", "b", "b").inOrder();
    assertEquals(3, ms.count(null));

    SortedSet<@Nullable String> elementSet = ms.elementSet();
    assertEquals(null, elementSet.first());
    assertEquals("b", elementSet.last());

    @RetainedLocalRef ListenableFuture<? extends I> localInputFuture = inputFuture;
    @RetainedLocalRef F localFunction = function;
    if (isCancelled() | localInputFuture == null | localFunction == null) {
      return;
    }
    inputFuture = null;

    if (localInputFuture.isCancelled()) {
      @SuppressWarnings("unchecked")
      boolean unused =

   *
   * @param key the non-null key whose value should be loaded
   * @param oldValue the non-null old value corresponding to {@code key}
   * @return the future new value associated with {@code key}; <b>must not be null, must not return
   *     null</b>
   * @throws Exception if unable to reload the result

     * @return {@link Logger}
     */
    public static synchronized Logger getLogger(final Class<?> clazz) {
        assertArgumentNotNull("clazz", clazz);

        if (!initialized) {
            initialize();
        }
        Logger logger = loggers.get(clazz);
        if (logger == null) {
            logger = new Logger(clazz);

            String artifactId,
            String version,
            String type,
            String classifier,
            Throwable t) {
        super(message, groupId, artifactId, version, type, classifier, null, null, t);
    }

    public ArtifactResolutionException(String message, Artifact artifact) {
        super(message, artifact);
    }

    @Override
    public PersistedToolchains build(File userToolchainsFile) throws MisconfiguredToolchainException {
        PersistedToolchains toolchains = null;

        if (userToolchainsFile != null && userToolchainsFile.isFile()) {
            try (InputStream in = Files.newInputStream(userToolchainsFile.toPath())) {

     *
     * @param versionRange The version range to match the current Maven runtime against, must not be {@code null}.
     * @return {@code true} if the current Maven runtime matches the specified version range, {@code false} otherwise.
     * @throws IllegalArgumentException If the specified version range is {@code null}, empty or otherwise not a valid
     *             version specification.
     */

                    final String fileName = getName(objectKey);
                    final ZonedDateTime lastModified =
                            s3Object.lastModified() != null ? s3Object.lastModified().atZone(java.time.ZoneId.systemDefault()) : null;
                    items.add(new StorageItem(fileName, prefix, false, s3Object.size(), lastModified, encodeId(objectKey)));
                }
            }

     * allowing the CAS below to succeed.
     */
    Thread currentThread = Thread.currentThread();
    if (!compareAndSet(null, currentThread)) {
      return; // someone else has run or is running.
    }

    boolean run = !isDone();
    T result = null;
    Throwable error = null;
    try {
      if (run) {
        result = runInterruptibly();