# Using Dataclasses { #using-dataclasses }

FastAPI is built on top of **Pydantic**, and I have been showing you how to use Pydantic models to declare requests and responses.

But FastAPI also supports using <a href="https://docs.python.org/3/library/dataclasses.html" class="external-link" target="_blank">`dataclasses`</a> the same way:

{* ../../docs_src/dataclasses_/tutorial001_py310.py hl[1,6:11,18:19] *}

     *
     * @return the start time as an Instant object, never {@code null}
     */
    @Nonnull
    Instant getStartTime();

    /**
     * Gets the directory of the topmost project being built, usually the current directory or the
     * directory pointed at by the {@code -f/--file} command line argument.
     *
     * @return the directory of the topmost project, never {@code null}
     * @see Project#isTopProject()

    @GwtIncompatible("java.lang.ref.WeakReference")
    public InternerBuilder weak() {
      this.strong = false;
      return this;
    }

    /**
     * Sets the concurrency level that will be used by the to-be-built {@link Interner}.
     *
     * @see MapMaker#concurrencyLevel(int)
     */
    @CanIgnoreReturnValue
    public InternerBuilder concurrencyLevel(int concurrencyLevel) {

 * }, executor);
 * }
 *
 * <h3>How to get an instance</h3>
 *
 * <p>We encourage you to return {@code ListenableFuture} from your methods so that your users can
 * take advantage of the {@linkplain Futures utilities built atop the class}. The way that you will
 * create {@code ListenableFuture} instances depends on how you currently create {@code Future}
 * instances:
 *
 * <ul>

    @GwtIncompatible("java.lang.ref.WeakReference")
    public InternerBuilder weak() {
      this.strong = false;
      return this;
    }

    /**
     * Sets the concurrency level that will be used by the to-be-built {@link Interner}.
     *
     * @see MapMaker#concurrencyLevel(int)
     */
    @CanIgnoreReturnValue
    public InternerBuilder concurrencyLevel(int concurrencyLevel) {

# CLAUDE.md - Fess Suggest Project Guide

> AI assistant guidance for the Fess Suggest project - a Java library providing intelligent search suggestions built on OpenSearch.

## Project Overview

**Fess Suggest** delivers auto-completion, search suggestions, and popular word analytics with multi-language support.

**Technology Stack:**
- Java 21+, Maven
- OpenSearch (provided dependency)
- Apache Lucene (query parsing, text analysis)

   * for a given key in sorted order, but it need not expose the <i>keys</i> in sorted order.
   * Individual {@code SortedSetMultimap} implementations, like those built with {@link
   * MultimapBuilder#treeKeys()}, may make additional guarantees.
   */
  @Override
  Map<K, Collection<V>> asMap();

  /**

             * the plugin Gradle distribution, this is only true at compile time.
             *
             * At runtime, the 'DefaultImportsReader' will be the version from the distribution actively being built/tested.
             */
            val clazz = DefaultImportsReader::class.java
            return clazz.getResource(RESOURCE)
                .readText()
                .split('\n')

 * constructed instance. To create session out of builder, use {@link SessionBuilder#build()}. For proper closing
 * of sessions, use {@link CloseableSession#close()} method on built instance(s).
 * <p>
 * Extend this class and override methods to customize, if needed.
 *
 * @since 4.0.0
 * @deprecated since 4.0.0, use {@code maven-api-impl} jar instead
 */
@Deprecated(since = "4.0.0")

   * for a given key in sorted order, but it need not expose the <i>keys</i> in sorted order.
   * Individual {@code SortedSetMultimap} implementations, like those built with {@link
   * MultimapBuilder#treeKeys()}, may make additional guarantees.
   */
  @Override
  Map<K, Collection<V>> asMap();

  /**