@CanIgnoreReturnValue
    public abstract Builder<E> add(E element);

    /**
     * Adds each element of {@code elements} to the {@code ImmutableCollection} being built.
     *
     * <p>Note that each builder class overrides this method in order to covariantly return its own
     * type.
     *
     * @param elements the elements to add
     * @return this {@code Builder} instance

    }

    /**
     * Adds {@code element} to the {@code ImmutableSortedMultiset}.
     *
     * @param element the element to add
     * @return this {@code Builder} object
     * @throws NullPointerException if {@code element} is null
     */
    @CanIgnoreReturnValue
    @Override
    public Builder<E> add(E element) {
      super.add(element);
      return this;
    }

    /**

            final String[] oldLabels = DocumentUtil.getValue(dataMap, fessConfig.getIndexFieldLabel(), String[].class);
            StreamUtil.stream(oldLabels).of(stream -> stream.forEach(newLabelSet::add));
            matchedLabelSet.stream().forEach(newLabelSet::add);
            dataMap.put(fessConfig.getIndexFieldLabel(), newLabelSet.toArray(new String[newLabelSet.size()]));
        }

        if (!dataMap.containsKey(fessConfig.getIndexFieldDocId())) {

								<group>root</group>
							</mapper>
						</data>
						<!-- Adds systemd file -->
						<data>
							<type>file</type>
							<src>${project.build.directory}/generated-packaging/deb/systemd/fess.service</src>
							<dst>${packaging.fess.systemd.dir}/fess.service</dst>
						</data>
						<!-- Adds systemd/sysctl.d configuration file -->
						<data>
							<type>file</type>

     * performing adds and removes in different ways.
     */
    runConcurrentlyMutatedTest(elements(), ops(add(1), add(2)), wrap);

    runConcurrentlyMutatedTest(elements(), ops(add(1), nop()), wrap);

    runConcurrentlyMutatedTest(elements(), ops(add(1), remove()), wrap);

    runConcurrentlyMutatedTest(elements(), ops(nop(), add(1)), wrap);

 * own subclass of {@link ListenableFuture}, complete with a method like {@link #from} to adapt an
 * existing {@code ListenableFuture}, implemented atop a {@link ForwardingListenableFuture} that
 * forwards to that future and adds the desired methods.
 */
@GwtCompatible
final class ForwardingFluentFuture<V extends @Nullable Object> extends FluentFuture<V> {
  private final ListenableFuture<V> delegate;

 *
 * @deprecated since 4.0.0, use {@link org.apache.maven.api.services} instead
 */
@Deprecated(since = "4.0.0")
public interface ProblemCollector {

    /**
     * Adds the specified problem.
     * Either message or exception is required
     *
     * @param severity The severity of the problem, must not be {@code null}.

    SetBuilderImpl<E> builder = new RegularSetBuilderImpl<>(6 + others.length);
    builder = builder.add(e1).add(e2).add(e3).add(e4).add(e5).add(e6);
    for (int i = 0; i < others.length; i++) {
      builder = builder.add(others[i]);
    }
    return builder.review().build();
  }

  /**

  }

  /** {@link RemovalListener} that adds all {@link RemovalNotification} objects to a queue. */
  @GwtIncompatible // ConcurrentLinkedQueue
  static class QueuingRemovalListener<K, V> extends ConcurrentLinkedQueue<RemovalNotification<K, V>>
      implements RemovalListener<K, V> {

    @Override
    public void onRemoval(RemovalNotification<K, V> notification) {
      add(notification);
    }
  }

  /**

// ConsoleLogger is introduced to workaround the dependency about logrus
type ConsoleLogger struct {
	Enable bool `json:"enable"`
}

// serverConfigV33 is just like version '32', removes clientID from NATS and MQTT, and adds queueDir, queueLimit in all notification targets.
type serverConfigV33 struct {
	quick.Config `json:"-"` // ignore interfaces

	Version string `json:"version"`

	// S3 API configuration.