# Dependencias Globales { #global-dependencies }

Para algunos tipos de aplicaciones, podrías querer agregar dependencias a toda la aplicación.

Similar a como puedes [agregar `dependencies` a los *path operation decorators*](dependencies-in-path-operation-decorators.md){.internal-link target=_blank}, puedes agregarlos a la aplicación de `FastAPI`.

En ese caso, se aplicarán a todas las *path operations* en la aplicación:

@GwtCompatible
public enum CollectionFeature implements Feature<Collection> {
  /**
   * The collection must not throw {@code NullPointerException} on calls such as {@code
   * contains(null)} or {@code remove(null)}, but instead must return a simple {@code false}.
   */
  ALLOWS_NULL_QUERIES,
  ALLOWS_NULL_VALUES(ALLOWS_NULL_QUERIES),

  /**
   * Indicates that a collection disallows certain elements (other than {@code null}, whose validity

Nestes casos, pode fazer sentido armazenar as tags em um `Enum`.

**FastAPI** suporta isso da mesma maneira que com strings simples:

{* ../../docs_src/path_operation_configuration/tutorial002b_py39.py hl[1,8:10,13,18] *}

## Resumo e descrição { #summary-and-description }

Você pode adicionar um `summary` e uma `description`:

 * TODO: javadoc.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@NullMarked
public abstract class TestStringListGenerator implements TestListGenerator<String> {
  @Override
  public SampleElements<String> samples() {
    return new Strings();
  }

  @Override
  public List<String> create(Object... elements) {
    String[] array = new String[elements.length];
    int i = 0;
    for (Object e : elements) {

 * @author Louis Wasserman
 */
@GwtCompatible
@NullMarked
public abstract class TestCharacterListGenerator implements TestListGenerator<Character> {
  @Override
  public SampleElements<Character> samples() {
    return new Chars();
  }

  @Override
  public List<Character> create(Object... elements) {
    Character[] array = new Character[elements.length];
    int i = 0;
    for (Object e : elements) {

/**
 * Creates collections containing unhashable sample elements, to be tested.
 *
 * @author Regina O'Dell
 */
@GwtCompatible
@NullMarked
public abstract class TestUnhashableCollectionGenerator<T extends Collection<UnhashableObject>>
    implements TestCollectionGenerator<UnhashableObject> {
  @Override
  public SampleElements<UnhashableObject> samples() {
    return new Unhashables();
  }

  @Override

Elle peut être une fonction asynchrone (`async def`) ou une fonction normale (`def`), **FastAPI** saura la gérer correctement.

Dans cet exemple, la fonction de tâche écrira dans un fichier (afin de simuler un envoi d'email).

L'opération d'écriture n'utilisant ni `async` ni `await`, on définit la fonction avec un `def` normal.

{* ../../docs_src/background_tasks/tutorial001.py hl[6:9] *}

## Ajouter une tâche d'arrière-plan

import assertk.assertions.startsWith
import com.github.ajalt.clikt.core.parse
import java.io.IOException
import kotlin.test.Test
import okhttp3.RequestBody
import okio.Buffer

class MainTest {
  @Test
  fun simple() {
    val request = fromArgs("http://example.com").createRequest()
    assertThat(request.method).isEqualTo("GET")
    assertThat(request.url.toString()).isEqualTo("http://example.com/")
    assertThat(request.body).isNull()

 * under the License.
 */
package org.apache.maven.building;

/**
 * Describes a problem that was encountered during settings building. A problem can either be an exception that was
 * thrown or a simple string message. In addition, a problem carries a hint about its source, e.g. the settings file
 * that exhibits the problem.
 *
 * @deprecated since 4.0.0, use {@link org.apache.maven.api.services} instead
 */

 * under the License.
 */
package org.apache.maven.building;

/**
 * Describes a problem that was encountered during settings building. A problem can either be an exception that was
 * thrown or a simple string message. In addition, a problem carries a hint about its source, e.g. the settings file
 * that exhibits the problem.
 *
 * @deprecated since 4.0.0, use {@link org.apache.maven.api.services} instead
 */