有些情境你可能想在測試時覆寫（override）某個相依（dependency）。

你不希望執行原本的相依（以及它可能具有的任何子相依）。

相反地，你想提供一個只在測試期間使用的不同相依（可能只在特定測試中），並回傳一個可以在原本相依值被使用之處使用的值。

### 使用情境：外部服務 { #use-cases-external-service }

例如你有一個需要呼叫的外部驗證提供者。

你傳送一個 token，它會回傳一個已驗證的使用者。

這個提供者可能按每個請求收費，而且呼叫它可能比在測試中使用固定的模擬使用者多花一些時間。

你大概只想對外部提供者測試一次，而不需要在每個測試都呼叫它。

在這種情況下，你可以覆寫用來呼叫該提供者的相依，並在測試中使用自訂的相依來回傳一個模擬使用者。

  /**
   * Cached value of #publicSuffixIndex(). Do not use directly.
   *
   * <p>Since this field isn't {@code volatile}, if an instance of this class is shared across
   * threads before it is initialized, then each thread is likely to compute their own copy of the
   * value.
   */
  @SuppressWarnings("Immutable")
  @LazyInit
  private int publicSuffixIndexCache = SUFFIX_NOT_INITIALIZED;

  /**

{* ../../docs_src/header_param_models/tutorial003_an_py310.py hl[19] *}

/// warning | Advertencia

Antes de establecer `convert_underscores` a `False`, ten en cuenta que algunos proxies y servidores HTTP no permiten el uso de headers con guiones bajos.

///

## Resumen { #summary }

    public ResolutionGroup retrieve(MetadataResolutionRequest request) throws ArtifactMetadataRetrievalException {
        Artifact artifact = request.getArtifact();

        //
        // If we have a system scoped artifact, then we do not want any searching in local or remote repositories,
        // and we want artifact resolution to only return the system scoped artifact itself.
        //

// when the object is uploaded in multiple parts via the S3
// multipart API. Instead, S3 first computes a MD5 of each part:
//
//	 e1 := MD5(part-1)
//	 e2 := MD5(part-2)
//	...
//	 eN := MD5(part-N)
//
// Then, the ETag of the object is computed as MD5 of all individual
// part checksums. S3 also encodes the number of parts into the ETag
// by appending a -<number-of-parts> at the end:
//
//	ETag := MD5(e1 || e2 || e3 ... || eN) || -N

			if value := env.Get(config.EnvMinIOPrometheusExtraLabels, ""); value != "" {
				os.Setenv("CONSOLE_PROMETHEUS_EXTRA_LABELS", value)
			}
		}
		// Support Prometheus Auth Token
		if value := env.Get(config.EnvMinIOPrometheusAuthToken, ""); value != "" {
			os.Setenv("CONSOLE_PROMETHEUS_AUTH_TOKEN", value)
		}
	}
	// Enable if LDAP is enabled.
	if globalIAMSys.LDAPConfig.Enabled() {

       * initialized by next() -- which initializes rowEntry, too.
       *
       * - rowEntry isn't cleared except below. If it was cleared below, then either
       *   columnIterator.remove() would have failed above (if the user hasn't called next() since
       *   then) or rowEntry would have been initialized by next() (as discussed above).
       */
      if (requireNonNull(rowEntry).getValue().isEmpty()) {

///

/// info | Información

Para declarar cookies, necesitas usar `Cookie`, porque de lo contrario los parámetros serían interpretados como parámetros de query.

///

/// info | Información

Ten en cuenta que, como **los navegadores manejan las cookies** de formas especiales y por detrás, **no** permiten fácilmente que **JavaScript** las toque.

                                                        data-href="${contextPath}/admin/dict/kuromoji/details/${f:u(dictId)}/4/${f:u(data.id)}">
                                                    <td>${f:h(data.token)}</td>
                                                    <td>${f:h(data.reading)}</td>
                                                </tr>
                                            </c:forEach>

        final PagingList<KuromojiItem> itemList = kuromojiFile.selectList(0, 5);
        for (int i = 0; i < itemList.size(); i++) {
            final KuromojiItem kuromojiItem = itemList.get(i);
            assertEquals("token" + (i + 1), kuromojiItem.getToken());
            assertEquals("seg" + (i + 1), kuromojiItem.getSegmentation());
            assertEquals("reading" + (i + 1), kuromojiItem.getReading());