The `TestClient` is based on <a href="https://www.python-httpx.org" class="external-link" target="_blank">HTTPX</a>, and luckily, we can use it directly to test the API.

## Example { #example }

For a simple example, let's consider a file structure similar to the one described in [Bigger Applications](../tutorial/bigger-applications.md){.internal-link target=_blank} and [Testing](../tutorial/testing.md){.internal-link target=_blank}:

objectClass: inetOrgPerson
cn: Alice Smith
sn: Smith
uid: alice1
mail: alice@example.io
userPassword: {SSHA}Yeh2/IV/q/HjG2yzN3YdE9CAF3EJFCLu

dn: uid=bobfisher,ou=people,ou=hwengg,dc=min,dc=io
objectClass: inetOrgPerson
cn: Robert Fisher
sn: Fisher
uid: bobfisher
mail: bob@example.io
userPassword: {SSHA}LktfbhK5oXSdDWCNzauJ9JA+Poxinl3y

dn: uid=cody3,ou=people,ou=hwengg,dc=min,dc=io

        // Test registerSmbURLHandler when java.protocol.handler.pkgs does not contain "jcifs"
        System.setProperty("java.protocol.handler.pkgs", "com.example");
        SingletonContext.registerSmbURLHandler();
        assertEquals("com.example|jcifs", System.getProperty("java.protocol.handler.pkgs"));
    }

    @Test
    void testRegisterSmbURLHandlerWhenPkgsAlreadyContainsJcifs() {

    @Mock
    private CredentialsInternal credentialsInternal;
    @Mock
    private SmbTransportImpl transport;

    private SmbSessionImpl newSession() {
        return new SmbSessionImpl(cifsContext, "server.example", "EXAMPLE", transport);
    }

    @BeforeEach
    void setup() {
        // Base context configuration - always needed
        when(cifsContext.getConfig()).thenReturn(configuration);

import javax.security.auth.callback.UnsupportedCallbackException
import okhttp3.OkHttpClient
import okhttp3.Request
import okhttp3.internal.SuppressSignatureCheck
import okhttp3.internal.platform.Platform

/**
 * Example of using a hardware key to perform client auth.
 * Prefer recent JDK builds, and results are temperamental to slight environment changes.
 * Different instructions and configuration may be required for other hardware devices.
 *

This document focuses on showing a working example on how to use Object Lambda with MinIO, you must have [MinIO deployed in your environment](https://docs.min.io/community/minio-object-store/operations/installation.html) before you can start using external lambda functions. You also must install Python version 3.8 or later for the lambda handlers to work.

## Example Lambda handler

Install the necessary dependencies.
```sh

### 3. Example

{* ../../docs_src/app_testing/test_main.py hl[3] *}


...and have the code for the tests just like before.

## Testing: extended example { #testing-extended-example }

Now let's extend this example and add more details to see how to test different parts.

### Extended **FastAPI** app file { #extended-fastapi-app-file }

Let's continue with the same file structure as before:

## Use Case { #use-case }

Let's start with an example **use case** and then see how to solve it with this.

Let's imagine that you have some **machine learning models** that you want to use to handle requests. 🤖

 *
 * <p>Example usage:</p>
 * <pre>
 * {@code
 * XPathAPI xPathAPI = new XPathAPI();
 * NodeList nodes = xPathAPI.selectNodeList(contextNode, "//example");
 * Node singleNode = xPathAPI.selectSingleNode(contextNode, "//example[1]");
 * XPathEvaluationResult<?> result = xPathAPI.eval(contextNode, "count(//example)");
 * }
 * </pre>
 *