public void testFirstNonNull_withNonNull() {
    String s1 = "foo";
    String s2 = MoreObjects.firstNonNull(s1, "bar");
    assertSame(s1, s2);

    Long n1 = 42L;
    Long n2 = MoreObjects.firstNonNull(null, n1);
    assertSame(n1, n2);

    Boolean b1 = true;
    Boolean b2 = MoreObjects.firstNonNull(b1, null);
    assertSame(b1, b2);
  }

  public void testFirstNonNull_throwsNullPointerException() {

    keyEquivalence = checkNotNull(equivalence);
    this.useCustomMap = true;
    return this;
  }

  Equivalence<Object> getKeyEquivalence() {
    return MoreObjects.firstNonNull(keyEquivalence, getKeyStrength().defaultEquivalence());
  }

  /**
   * Sets the minimum total size for the internal hash tables. For example, if the initial capacity

      if (eventSubscribers == null) {
        CopyOnWriteArraySet<Subscriber> newSet = new CopyOnWriteArraySet<>();
        eventSubscribers =
            MoreObjects.firstNonNull(subscribers.putIfAbsent(eventType, newSet), newSet);
      }

      eventSubscribers.addAll(eventMethodsInListener);
    }
  }

  /** Unregisters all subscribers on the given listener object. */

    keyEquivalence = checkNotNull(equivalence);
    this.useCustomMap = true;
    return this;
  }

  Equivalence<Object> getKeyEquivalence() {
    return MoreObjects.firstNonNull(keyEquivalence, getKeyStrength().defaultEquivalence());
  }

  /**
   * Sets the minimum total size for the internal hash tables. For example, if the initial capacity

      if (eventSubscribers == null) {
        CopyOnWriteArraySet<Subscriber> newSet = new CopyOnWriteArraySet<>();
        eventSubscribers =
            MoreObjects.firstNonNull(subscribers.putIfAbsent(eventType, newSet), newSet);
      }

      eventSubscribers.addAll(eventMethodsInListener);
    }
  }

  /** Unregisters all subscribers on the given listener object. */

        String className = details.getPluginClass().getName();
        String pluginId = details.getPluginId();
        String displayName = MoreObjects.firstNonNull(pluginId, className);
        return new DefaultBinaryPluginIdentifier(displayName, className, pluginId);
    }

   * @throws NullPointerException if both {@code first} and {@code second} are null
   * @since 18.0 (since 3.0 as {@code Objects.firstNonNull()}).
   */
  public static <T> T firstNonNull(@CheckForNull T first, @CheckForNull T second) {
    if (first != null) {
      return first;
    }
    if (second != null) {
      return second;
    }

    keyEquivalence = checkNotNull(equivalence);
    return this;
  }

  Equivalence<Object> getKeyEquivalence() {
    return MoreObjects.firstNonNull(keyEquivalence, getKeyStrength().defaultEquivalence());
  }

  /**
   * Sets a custom {@code Equivalence} strategy for comparing values.
   *

  // e.g. Optional<URL> tryGetResource or boolean resourceExists
  public static URL getResource(String resourceName) {
    ClassLoader loader =
        MoreObjects.firstNonNull(
            Thread.currentThread().getContextClassLoader(), Resources.class.getClassLoader());
    URL url = loader.getResource(resourceName);
    checkArgument(url != null, "resource %s not found.", resourceName);

   * @throws NullPointerException if both {@code first} and {@code second} are null
   * @since 18.0 (since 3.0 as {@code Objects.firstNonNull()}).
   */
  public static <T> T firstNonNull(@CheckForNull T first, @CheckForNull T second) {
    if (first != null) {
      return first;
    }
    if (second != null) {
      return second;
    }