* getChecked(future, WillBeUnloadedException.class)}, and returns the loader. The caller can then
   * test that the {@code ClassLoader} can still be GCed. The test amounts to a test that {@code
   * getChecked} holds no strong references to the class.
   */
  private WeakReference<?> doTestClassUnloading() throws Exception {
    URLClassLoader shadowLoader = new URLClassLoader(parseJavaClassPath(), null);
    @SuppressWarnings("unchecked")

   * getChecked(future, WillBeUnloadedException.class)}, and returns the loader. The caller can then
   * test that the {@code ClassLoader} can still be GCed. The test amounts to a test that {@code
   * getChecked} holds no strong references to the class.
   */
  private WeakReference<?> doTestClassUnloading() throws Exception {
    URLClassLoader shadowLoader = new URLClassLoader(parseJavaClassPath(), null);
    @SuppressWarnings("unchecked")

 *           .thenComparing(foo -> foo.anEnum, nullsLast(naturalOrder()));
 *
 *   @Override
 *   public int compareTo(Foo that) {
 *     return COMPARATOR.compare(this, that);
 *   }
 * }
 *
 * <p>With method references it is more succinct: {@code comparing(Foo::aString)} for example.
 *
 * <p>Using {@link Comparator} avoids certain types of bugs, for example when you meant to write

            }
        }
        return hash;
    }

    /**
     * Appends line numbers to each line of content with a given prefix.
     * Useful for debugging and displaying content with line references.
     *
     * @param prefix the prefix to add before each line number
     * @param content the content to add line numbers to
     * @return the content with line numbers prepended, or empty string if content is blank

 * by individual libraries that provide specialized support for particular use cases.
 *
 * <p>Disadvantages of EventBus include:
 *
 * <ul>
 *   <li>It makes the cross-references between producer and subscriber harder to find. This can
 *       complicate debugging, lead to unintentional reentrant calls, and force apps to eagerly
 *       initialize all possible subscribers at startup time.

        // Then
        assertNotSame(instance1, instance2);
        assertEquals(instance1.getCommand(), instance2.getCommand());
        assertNotEquals(instance1.toString(), instance2.toString()); // Different object references in toString
    }

    /**
     * Test thread safety of read/write operations
     */
    @Test
    @DisplayName("Test thread safety of operations")

        partitionedFiles.put(currentVersion, mutableAllFilesInCheckout);

        return partitionedFiles;
    }

    /**
     * Ensure the upstream git remote is up-to-date. The upstream is whatever git remote references `elastic/elasticsearch`.
     * @param gitWrapper used to call `git`
     */
    private static void findAndUpdateUpstreamRemote(GitWrapper gitWrapper) {
        LOGGER.info("Finding upstream git remote");

   * null.
   *
   * <p><b>Discouraged:</b> Prefer using either {@code x -> x == null} or {@code Objects::isNull},
   * but note that lambdas and method references do not have human-readable {@link #toString()}
   * representations and are not serializable.
   */
  public static <T extends @Nullable Object> Predicate<T> isNull() {
    return ObjectPredicate.IS_NULL.withNarrowedType();

        ReferenceQueue<V> queue, @Nullable V value, ReferenceEntry<K, V> entry);

    /**
     * Notify pending loads that a new value was set. This is only relevant to loading value
     * references.
     */
    void notifyNewValue(@Nullable V newValue);

    /**
     * Returns true if a new value is currently loading, regardless of whether there is an existing

   * Returns an array containing all of the elements in the specified collection. This method
   * returns the elements in the order they are returned by the collection's iterator. The returned
   * array is "safe" in that no references to it are maintained by the collection. The caller is
   * thus free to modify the returned array.
   *
   * <p>This method assumes that the collection size doesn't change while the method is running.
   *