All this might seem contrived. And it might not be very clear how is it useful yet.

These examples are intentionally simple, but show how it all works.

In the chapters about security, there are utility functions that are implemented in this same way.

If you understood all this, you already know how those utility tools for security work underneath.

<!--- If suggesting a change/improvement, explain the difference from current behavior -->

## Possible Solution
<!--- Not obligatory, but suggest a fix/reason for the bug, -->
<!--- or ideas how to implement the addition or change -->

## Steps to Reproduce (for bugs)
<!--- Provide a link to a live example, or an unambiguous set of steps to -->
<!--- reproduce this bug. Include code to reproduce, if relevant -->

name: Feature request
about: Suggest an idea
title: ''
labels: enhancement
assignees: ''

---

Start by telling us what problem you’re trying to solve. Often a solution already exists!

 *
 * @author Kevin Bourrillion
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
abstract class AbstractMapBasedMultiset<E extends @Nullable Object> extends AbstractMultiset<E>
    implements Serializable {

  transient ObjectCountHashMap<E> backingMap;
  transient long size;

  AbstractMapBasedMultiset(int distinctElements) {
    backingMap = newBackingMap(distinctElements);
  }

 * under the License.
 */
package org.apache.maven.repository;

import org.apache.maven.artifact.handler.ArtifactHandler;

/**
 * Assists unit testing.
 *
 */
@Deprecated
class TestArtifactHandler implements ArtifactHandler {

    private String type;

    private String extension;

    public TestArtifactHandler(String type) {
        this(type, type);
    }

 * {@link #sloppyTearDown()} instead.
 *
 * @author Luiz-Otavio Zorzella
 * @since 10.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public abstract class SloppyTearDown implements TearDown {
  private static final Logger logger = Logger.getLogger(SloppyTearDown.class.getName());

  @Override
  public final void tearDown() {
    try {
      sloppyTearDown();
    } catch (Throwable t) {

        .build();

    try (Response response = client.newCall(request).execute()) {
      System.out.println(response.request().header("Date"));
    }
  }

  static class CurrentDateInterceptor implements Interceptor {
    @Override public Response intercept(Chain chain) throws IOException {
      Request request = chain.request();
      Headers newHeaders = request.headers()
          .newBuilder()

 *
 * @author Bob Lee
 * @since 2.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public abstract class FinalizablePhantomReference<T> extends PhantomReference<T>
    implements FinalizableReference {
  /**
   * Constructs a new finalizable phantom reference.
   *
   * @param referent to phantom reference
   * @param queue that should finalize the referent
   */

 */
package org.codelibs.fess.crawler.entity;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

/**
 * @author shinsuke
 *
 */
public class SitemapSet implements Serializable {

    private static final long serialVersionUID = 1L;

    public static final String URLSET = "UrlSet";

    public static final String INDEX = "Index";

import org.codelibs.fess.crawler.rule.Rule;
import org.codelibs.fess.crawler.rule.RuleManager;

import jakarta.annotation.Resource;

/**
 * @author shinsuke
 *
 */
public abstract class AbstractRule implements Rule {

    private static final long serialVersionUID = 1L;

    protected String ruleId;

    protected ResponseProcessor responseProcessor;

    @Resource
    protected CrawlerContainer crawlerContainer;