Routes are declared in a single place, using functions declared in other places (instead of using decorators that can be placed right on top of the function that handles the endpoint). This is closer to how Django does it than to how Flask (and Starlette) does it. It separates in the code things that are relatively tightly coupled.

/// check | "Inspired **FastAPI** to"

# Async Tests

You have already seen how to test your **FastAPI** applications using the provided `TestClient`. Up to now, you have only seen how to write synchronous tests, without using `async` functions.

  public static Test suite() {
    TestSuite suite = new TestSuite();

    suite.addTest(transformSuite());
    suite.addTest(filterSuite());

    suite.addTest(
        ListMultimapTestSuiteBuilder.using(
                new TestStringListMultimapGenerator() {
                  @Override
                  protected ListMultimap<String, String> create(Entry<String, String>[] entries) {

    return emptySet();
  }

  protected Collection<Method> suppressForVector() {
    return emptySet();
  }

  public Test testsForEmptyList() {
    return ListTestSuiteBuilder.using(
            new TestStringListGenerator() {
              @Override
              public List<String> create(String[] elements) {
                return emptyList();
              }
            })

    return emptySet();
  }

  protected Collection<Method> suppressForVector() {
    return emptySet();
  }

  public Test testsForEmptyList() {
    return ListTestSuiteBuilder.using(
            new TestStringListGenerator() {
              @Override
              public List<String> create(String[] elements) {
                return emptyList();
              }
            })

# 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.py hl[1,7:12,19:20] *}

    return emptySet();
  }

  protected Collection<Method> suppressForPriorityQueue() {
    return emptySet();
  }

  public Test testsForArrayDeque() {
    return QueueTestSuiteBuilder.using(
            new TestStringQueueGenerator() {
              @Override
              public Queue<String> create(String[] elements) {
                return new ArrayDeque<>(MinimalCollection.of(elements));
              }

            .createTestSuite());

    suite.addTest(
        MultisetTestSuiteBuilder.using(unionGenerator())
            .withFeatures(CollectionSize.ANY, CollectionFeature.ALLOWS_NULL_VALUES)
            .named("Multisets.union")
            .createTestSuite());

    suite.addTest(
        MultisetTestSuiteBuilder.using(intersectionGenerator())
            .withFeatures(
                CollectionSize.ANY,

 * <pre>{@code
 * // won't work
 * TreeTraverser<NodeType> traverser = node -> node.getChildNodes();
 * }</pre>
 *
 * Instead, you can pass a lambda expression to the {@code using} factory method:
 *
 * <pre>{@code
 * TreeTraverser<NodeType> traverser = TreeTraverser.using(node -> node.getChildNodes());
 * }</pre>
 *
 * @author Louis Wasserman
 * @since 15.0

            .createTestSuite());

    suite.addTest(
        MultisetTestSuiteBuilder.using(unionGenerator())
            .withFeatures(CollectionSize.ANY, CollectionFeature.ALLOWS_NULL_VALUES)
            .named("Multisets.union")
            .createTestSuite());

    suite.addTest(
        MultisetTestSuiteBuilder.using(intersectionGenerator())
            .withFeatures(
                CollectionSize.ANY,