│   ├── collection/     # Enhanced collection utilities
│   ├── convert/        # Type conversion utilities
│   ├── exception/      # Runtime exception wrappers
│   ├── io/            # I/O and resource management
│   ├── lang/          # Reflection and language utilities
│   ├── log/           # Logging abstraction
│   ├── text/          # Text processing utilities
│   ├── xml/           # XML processing utilities

 *
 * <h2>Contents</h2>
 *
 * <h3>Value types</h3>
 *
 * <ul>
 *   <li>{@link ImmutableDoubleArray}
 *   <li>{@link ImmutableIntArray}
 *   <li>{@link ImmutableLongArray}
 *   <li>{@link UnsignedInteger}
 *   <li>{@link UnsignedLong}
 * </ul>
 *
 * <h3>Per-type static utilities</h3>
 *
 * <ul>
 *   <li>{@link Booleans}

 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

/**
 * Concurrency utilities.
 *
 * <p>Commonly used types include {@link ClosingFuture}, {@link ListenableFuture}, and {@link
 * Service}.
 *
 * <p>Commonly used utilities include {@link Futures}, {@link MoreExecutors}, {@link
 * ThreadFactoryBuilder}, and {@link Uninterruptibles}.
 *

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * Testing utilities. This package is a part of the open-source <a
 * href="https://github.com/google/guava">Guava</a> library.
 */
@CheckReturnValue
@NullMarked
package com.google.common.testing;

    <artifactId>plexus</artifactId>
    <groupId>org.codehaus.plexus</groupId>
    <version>1.0.4</version>
  </parent>
  <modelVersion>4.0.0</modelVersion>
  <artifactId>plexus-utils</artifactId>
  <name>Plexus Common Utilities</name>
  <version>1.1</version>
  <build>
    <plugins>
      <plugin>
        <artifactId>maven-surefire-plugin</artifactId>
        <configuration>
          <excludes>

The most complex problem is building an authentication/authorization provider like those, but **FastAPI** gives you the tools to do it easily, while doing the heavy lifting for you.

///

## **FastAPI** utilities { #fastapi-utilities }

FastAPI provides several tools for each of these security schemes in the `fastapi.security` module that simplify using these security mechanisms.

# Use Old 403 Authentication Error Status Codes { #use-old-403-authentication-error-status-codes }

Before FastAPI version `0.122.0`, when the integrated security utilities returned an error to the client after a failed authentication, they used the HTTP status code `403 Forbidden`.

 * the License.
 */

/**
 * {@linkplain CacheBuilder Discouraged} (in favor of <a
 * href="https://github.com/ben-manes/caffeine/wiki">Caffeine</a>) caching utilities.
 *
 * <p>The core interface used to represent caches is {@link Cache}. In-memory caches can be
 * configured and created using {@link CacheBuilder}, with cache entries being loaded by {@link

import java.util.concurrent.Executor;
import java.util.concurrent.Future;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.atomic.AtomicBoolean;
import org.jspecify.annotations.Nullable;

/**
 * Utilities necessary for working with libraries that supply plain {@link Future} instances. Note
 * that, whenever possible, it is strongly preferred to modify those libraries to return {@code
 * ListenableFuture} directly.
 *

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.service;

/**
 * Abstract base class for Fess application services.
 * This class provides common functionality and utilities for service implementations
 * throughout the Fess search application.
 */
public abstract class FessAppService {

    /**
     * Default constructor.
     */
    public FessAppService() {