When deploying applications you will probably want to have some **replication of processes** to take advantage of **multiple cores** and to be able to handle more requests.

As you saw in the previous chapter about [Deployment Concepts](concepts.md){.internal-link target=_blank}, there are multiple strategies you can use.

If you integrate your API with an OAuth2 provider, you will be able to authenticate and come back to the API docs with the acquired credentials. And interact with it using the real OAuth2 authentication.

Swagger UI will handle it behind the scenes for you, but it needs this "redirect" helper.

///

### Create a *path operation* to test it { #create-a-path-operation-to-test-it }

	if confRegion == "" {
		return true
	}
	if confRegion == "US" {
		confRegion = globalMinioDefaultRegion
	}
	// Some older s3 clients set region as "US" instead of
	// globalMinioDefaultRegion, handle it.
	if reqRegion == "US" {
		reqRegion = globalMinioDefaultRegion
	}
	return reqRegion == confRegion
}

// check if the access key is valid and recognized, additionally

    resp, err := instance.Call(ctx, conn, grid.NewMSSWith(map[string]string{"myfield": "myvalue"}))
    if err == nil {
        fmt.Println("Got response with field", resp["result"])
    }
```

The wrapper will handle all serialization and de-serialization of the request and response,
and furthermore provides reuse of the structs used for the request and response.

        ProjectBuildingException exception = new ProjectBuildingException(results);
        String message = exception.getMessage();

        assertTrue(message.contains("[unknown project]"), "Message should handle unknown project gracefully");
    }

public interface Mojo {
    /**
     * Executes the behavior defined by this {@code Mojo}. This method is invoked
     * during the Maven build lifecycle to perform the Mojo's designated task.
     *
     * <p>Implementations should handle any task-specific logic and may communicate
     * errors by throwing an {@link Exception}. Error conditions should provide
     * sufficient detail to aid troubleshooting.</p>
     *

        // Remove trailing slash unless it's the root
        if (normalized.length() > 1 && normalized.endsWith("\\")) {
            normalized = normalized.substring(0, normalized.length() - 1);
        }

        // Handle current directory references
        normalized = normalized.replace("\\.", "");
        normalized = normalized.replace(".\\", "");

        return normalized;
    }

    /**
     * Validate UNC path

    @Mock
    private SmbResourceLocator locator;

    @Mock
    private Configuration config;

    @Mock
    private CIFSContext cifsContext;

    @BeforeEach
    void setup() {
        // Tree handle lifecycle and config
        lenient().when(tree.acquire()).thenReturn(tree);
        lenient().when(tree.isConnected()).thenReturn(true);

        // CIFS context returns same config to build responses during initResponse

        }
        return super.hookBefore(runtime);
    }

    /**
     * Returns the login manager for this action. Search actions do not require
     * a login manager as they handle authentication differently.
     *
     * @return an empty OptionalThing as search actions don't use login managers
     */
    @Override
    protected OptionalThing<LoginManager> myLoginManager() {

Let's say you have a custom exception `UnicornException` that you (or a library you use) might `raise`.

And you want to handle this exception globally with FastAPI.

You could add a custom exception handler with `@app.exception_handler()`:

{* ../../docs_src/handling_errors/tutorial003_py39.py hl[5:7,13:18,24] *}