* 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.

    /**
     * Returns the entry associated with this value reference, or {@code null} if this value
     * reference is independent of any entry.
     */
    @Nullable ReferenceEntry<K, V> getEntry();

    /**
     * Creates a copy of this reference for the given entry.
     *
     * <p>{@code value} may be null only for a loading reference.
     */
    ValueReference<K, V> copyFor(

  }

  /**
   * Returns a predicate that evaluates to {@code true} if the object reference being tested is
   * 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.
   */

 *           .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

   * 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")

            }
        }
        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

        // 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")

   * about arrays for now, as they're a mess.
   */
  public static <T extends @Nullable Object> T[] newArray(T[] reference, int length) {
    T[] empty = reference.length == 0 ? reference : Arrays.copyOf(reference, 0);
    return Arrays.copyOf(empty, length);
  }

  /**
   * Returns a new array that contains the concatenated contents of two arrays.
   *

        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");