That's one of the main things that **FastAPI** adds on top, all based on Python type hints (using Pydantic). That, plus the dependency injection system, security utilities, OpenAPI schema generation, etc.

/// note | Technical Details

 *   <li>Running tasks <i>cannot</i> be interrupted. (Note that {@code newSequentialExecutor} does
 *       not return {@code Future} objects, so it doesn't support interruption directly, either.
 *       However, utilities that <i>use</i> that executor have the ability to interrupt tasks
 *       running on it. This class, by contrast, does not expose an {@code Executor} API.)
 * </ul>
 *

import java.nio.charset.Charset;
import java.util.Arrays;
import java.util.Random;
import java.util.Set;
import org.jspecify.annotations.NullUnmarked;
import org.junit.Assert;

/**
 * Various utilities for testing {@link HashFunction}s.
 *
 * @author Dimitris Andreou
 * @author Kurt Alfred Kluever
 */
@NullUnmarked
final class HashTestUtils {
  private HashTestUtils() {}

import java.util.zip.Checksum;
import javax.crypto.spec.SecretKeySpec;
import org.jspecify.annotations.Nullable;

/**
 * Static methods to obtain {@link HashFunction} instances, and other static hashing-related
 * utilities.
 *
 * <p>A comparison of the various hash functions can be found <a
 * href="https://docs.google.com/spreadsheets/d/1_q2EVcxA2HjcrlVMbaqXwMj31h9M5-Bqj_m8vITOwwk/">here</a>.
 *
 * @author Kevin Bourrillion

_clearfix.scss","../../scss/_spinners.scss","../../scss/utilities/_align.scss","../../scss/mixins/_background-variant.scss","../../scss/utilities/_background.scss","../../scss/utilities/_borders.scss","../../scss/utilities/_display.scss","../../scss/utilities/_embed.scss","../../scss/utilities/_flex.scss","../../scss/utilities/_float.scss","../../scss/utilities/_interactions.scss","../../scss/utilities/_overflow.scss","../../scss/utilities/_position.scss","../../scss/utilities/_screenreaders.scs...

 * neither Unicode-aware nor locale-dependent.
 *
 * <p>See the Guava User Guide article on <a
 * href="https://github.com/google/guava/wiki/PrimitivesExplained">primitive utilities</a>.
 *
 * @author Kevin Bourrillion
 * @since 1.0
 */
@GwtCompatible
public final class Chars {
  private Chars() {}

  /**
   * The number of bytes required to represent a primitive {@code char} value.

 * {@link Integer} or {@link Arrays}.
 *
 * <p>See the Guava User Guide article on <a
 * href="https://github.com/google/guava/wiki/PrimitivesExplained">primitive utilities</a>.
 *
 * @author Kevin Bourrillion
 * @since 1.0
 */
@GwtCompatible
public final class Ints extends IntsMethodsForWeb {
  private Ints() {}

  /**

import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpSession;

/**
 * Helper class for handling view-related operations in the Fess search system.
 * This class provides utilities for content rendering, URL processing, highlighting,
 * caching, pagination, and user interface functionality.
 *
 */
public class ViewHelper {

    /**
     * Default constructor for ViewHelper.
     */

import com.google.common.cache.LoadingCache;
import com.ibm.icu.util.ULocale;

import jakarta.annotation.PostConstruct;
import jakarta.annotation.PreDestroy;

/**
 * Helper class for system-level operations and utilities.
 * This class provides methods for managing system properties, handling JSP files,
 * normalizing configurations, and other system-related tasks.
 */
public class SystemHelper {

    /**

 * either {@link Double} or {@link Arrays}.
 *
 * <p>See the Guava User Guide article on <a
 * href="https://github.com/google/guava/wiki/PrimitivesExplained">primitive utilities</a>.
 *
 * @author Kevin Bourrillion
 * @since 1.0
 */
@GwtCompatible
public final class Doubles extends DoublesMethodsForWeb {
  private Doubles() {}

  /**