* They are created when <dfn>resolving</dfn> an {@code ArtifactCoordinates}. Resolving is the process
 * that selects a particular version and downloads the artifact in the local repository.
 * There are two sub-interfaces, {@link org.apache.maven.api.DownloadedArtifact} which is used when
 * an artifact has been resolved</p>
 *
 * <p>{@link org.apache.maven.api.DependencyCoordinates} instances are used to express a dependency.

---

## **Typer**, le FastAPI des <abbr title="Command Line Interface">CLI</abbr>

<a href="https://typer.tiangolo.com" target="_blank"><img src="https://typer.tiangolo.com/img/logo-margin/logo-margin-vector.svg" style="width: 20%;"></a>

  /**
   * Flattens a class's type hierarchy into a set of {@code Class} objects including all
   * superclasses (transitively) and all interfaces implemented by these superclasses.
   */
  @VisibleForTesting
  static ImmutableSet<Class<?>> flattenHierarchy(Class<?> concreteClass) {
    return flattenHierarchyCache.getUnchecked(concreteClass);
  }

* **Validar datos**: viniendo de cada request:
    * Generando **errores automáticos** devueltos al cliente cuando los datos son inválidos.
* **Documentar** la API usando OpenAPI:
    * que en su caso es usada por las interfaces de usuario de la documentación automática e interactiva.

Puede que todo esto suene abstracto. Pero no te preocupes que todo lo verás en acción en el [Tutorial - User Guide](tutorial/index.md){.internal-link target=_blank}.

      represent, as a whole, an original work of authorship. For the purposes
      of this License, Derivative Works shall not include works that remain
      separable from, or merely link (or bind by name) to the interfaces of,
      the Work and Derivative Works thereof.

      "Contribution" shall mean any work of authorship, including
      the original version of the Work and any modifications or additions

   *
   * <p>Java 8 introduced a new method {@code getAnnotatedBounds()} in the {@link TypeVariable}
   * interface, whose return type {@code AnnotatedType[]} is also new in Java 8. That means that we
   * cannot implement that interface in source code in a way that will compile on both Java 7 and
   * Java 8. If we include the {@code getAnnotatedBounds()} method then its return type means it

      represent, as a whole, an original work of authorship. For the purposes
      of this License, Derivative Works shall not include works that remain
      separable from, or merely link (or bind by name) to the interfaces of,
      the Work and Derivative Works thereof.

      "Contribution" shall mean any work of authorship, including
      the original version of the Work and any modifications or additions

    * `datetime` objects.
    * `UUID` objects.
    * Database models.
    * ...and many more.
* Automatic interactive API documentation, including 2 alternative user interfaces:
    * Swagger UI.
    * ReDoc.

---

Coming back to the previous code example, **FastAPI** will:

* Validate that there is an `item_id` in the path for `GET` and `PUT` requests.

    * `datetime` objects.
    * `UUID` objects.
    * Database models.
    * ...and many more.
* Automatic interactive API documentation, including 2 alternative user interfaces:
    * Swagger UI.
    * ReDoc.

---

Coming back to the previous code example, **FastAPI** will:

* Validate that there is an `item_id` in the path for `GET` and `PUT` requests.

</p>

<p>
By construction, an interface's type set never contains an interface type.
</p>

<pre>
// An interface representing only the type int.
interface {
	int
}

// An interface representing all types with underlying type int.
interface {
	~int
}

// An interface representing all types with underlying type int that implement the String method.