}

	meta, err := loadBucketMetadataParse(ctx, objAPI, bucket, parse)
	if err != nil {
		if !globalIsErasure && !globalIsDistErasure && errors.Is(err, errVolumeNotFound) {
			// Only single drive mode needs this fallback.
			meta = newBucketMetadata(bucket)
		} else {
			return updatedAt, err
		}
	}
	updatedAt = UTCNow()
	switch configFile {
	case bucketPolicyConfig:
		meta.PolicyConfigJSON = configData

Por ejemplo, si algún código en algún punto intermedio, en otra dependencia o en una *path operation*, realiza un "rollback" en una transacción de base de datos o crea cualquier otro error, recibirás la excepción en tu dependencia.

Por lo tanto, puedes buscar esa excepción específica dentro de la dependencia con `except SomeException`.

        if (startBracket != -1 && endBracket != -1 && endBracket > startBracket) {
            return transportStr.substring(startBracket + 1, endBracket);
        }
        // Fallback: just use address
        return transport.getRemoteAddress().getHostAddress();
    }

    /**
     * Get connection key from address and port
     */

        try (SmbSessionImpl treesess = t.getSession()) {
            if (treesess.getCredentials().isAnonymous() || treesess.getCredentials().isGuest()) {
                // refresh anonymous session or fallback to anonymous from guest login
                try (SmbSessionInternal s =
                        trans.getSmbSession(this.ctx.withAnonymousCredentials(), treesess.getTargetHost(), treesess.getTargetDomain())

            } finally {
                SMailCallbackContext.clearPreparedMessageHookOnThread();
            }
        }
    }

    /**
     * Retrieves a value from a map with a default fallback.
     *
     * @param dataMap the map to retrieve the value from
     * @param key the key to look up
     * @param defaultValue the default value to return if key is not found or value is blank

                showCopySuccess(button);
            }).catch(function() {
                showCopyError(button);
            });
        } else {
            // Fallback for older browsers
            var textarea = document.createElement('textarea');
            textarea.value = text;
            textarea.style.position = 'fixed';
            textarea.style.opacity = '0';

                            "Expected root element 'extensions' but found '" + parser.getName() + "'", parser, null);
                } else if (parsed) {
                    // fallback, already expected a XmlPullParserException due to invalid XML
                    throw new XmlPullParserException("Duplicated tag: 'extensions'", parser, null);
                }

                        || isPackagedArtifactUpToDate(project, packagedArtifactFile))) {
            return packagedArtifactFile;
        }

        if (!hasBeenPackagedDuringThisSession(project)) {
            // fallback to loose class files only if artifacts haven't been packaged yet
            // and only for plain old jars. Not war files, not ear files, not anything else.

            if (entry.getInconsistencyCount() > 5) {
                entry.invalidate();
            }
        }
    }
}
```

### 9.2 Fallback Mechanisms
```java
public class DirectoryOperationFallback {
    public SmbFile[] safeListFiles(SmbFile directory) throws IOException {
        try {
            // Try cached listing first

你可以使用 `async` 或一般函式。

**FastAPI** 都會正確處理，和一般相依相同。

///

## 同時使用 `yield` 與 `try` 的相依 { #a-dependency-with-yield-and-try }

如果在含 `yield` 的相依中使用 `try` 區塊，你會接收到使用該相依時拋出的任何例外。

例如，如果在中途的某段程式碼、其他相依，或某個路徑操作中，讓資料庫交易「rollback」或產生了任何例外，你都會在你的相依中接收到該例外。

因此，你可以在相依內用 `except SomeException` 來攔截特定例外。

同樣地，你可以使用 `finally` 來確保無論是否有例外都會執行結束步驟。

{* ../../docs_src/dependencies/tutorial007_py310.py hl[3,5] *}