import java.util.zip.Checksum;
import javax.annotation.CheckForNull;
import javax.crypto.spec.SecretKeySpec;

/**
 * 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

 *   <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.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.charset.Charset;
import java.util.Arrays;
import java.util.Random;
import java.util.Set;
import org.junit.Assert;

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

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"

import java.nio.charset.StandardCharsets;

/**
 * Static methods pertaining to ASCII characters (those in the range of values {@code 0x00} through
 * {@code 0x7F}), and to strings containing such characters.
 *
 * <p>ASCII utilities also exist in other classes of this package:
 *
 * <ul>
 *   <!-- TODO(kevinb): how can we make this not produce a warning when building gwt javadoc? -->

 * {@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(emulated = true)
@ElementTypesAreNonnullByDefault
public final class Ints extends IntsMethodsForWeb {
  private Ints() {}

  /**

 * 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(emulated = true)
@ElementTypesAreNonnullByDefault
public final class Chars {
  private Chars() {}

  /**

_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...

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Provides utility methods for working with {@linkplain File files}.
 *
 * <p>{@link java.nio.file.Path} users will find similar utilities in {@link MoreFiles} and the
 * JDK's {@link java.nio.file.Files} class.
 *
 * @author Chris Nokleberg
 * @author Colin Decker
 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible

 * 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(emulated = true)
@ElementTypesAreNonnullByDefault
public final class Doubles extends DoublesMethodsForWeb {
  private Doubles() {}