1. Script the mocks.
2. Run application code.
3. Verify that the expected requests were made.

Here's a complete example:

### Java
```java
public void test() throws Exception {
  // Create a MockWebServer. These are lean enough that you can create a new
  // instance for every unit test.
  MockWebServer server = new MockWebServer();

  // Schedule some responses.
  server.enqueue(new MockResponse.Builder()
      .body("hello, world!")

## Crea un Pull Request { #create-a-pull-request }

Puedes [contribuir](contributing.md){.internal-link target=_blank} al código fuente con Pull Requests, por ejemplo:

* Para corregir un error tipográfico que encontraste en la documentación.

      implements TestListGenerator<Entry<String, Integer>> {
    @Override
    public List<Entry<String, Integer>> create(Object... elements) {
      return (List<Entry<String, Integer>>) super.create(elements);
    }
  }

  public static Test suite() {
    TestSuite suite = new TestSuite();

    suite.addTest(transformSuite());
    suite.addTest(filterSuite());

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[9] *}

In this case, **FastAPI** won't ever touch or care about `__init__`, we will use it directly in our code.

## Create an instance { #create-an-instance }

We could create an instance of this class with:

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[18] *}

        // Arrange
        stubAcquireReturnsSelf();
        List<FileEntry[]> pages = List.of(new FileEntry[][] { new FileEntry[] {} });

        // Create iterator where open() returns null by giving null initial
        TestIterator it = TestIterator.create(tree, parent, "*", null, 0, null, pages);

        // Assert
        assertFalse(it.hasNext(), "No next when opened with null initial");

err != nil { return err } s.initBlock = bytes.Clone(b[marshaledSize:]) return nil } // NewShake128 creates a new SHAKE128 XOF. func NewShake128() *SHAKE { return &SHAKE{d: Digest{rate: rateK256, outputLen: 32, dsbyte: dsbyteShake}} } // NewShake256 creates a new SHAKE256 XOF. func NewShake256() *SHAKE { return &SHAKE{d: Digest{rate: rateK512, outputLen: 64, dsbyte: dsbyteShake}} } // NewCShake128 creates a new cSHAKE128 XOF. // // N is used to define functions based on cSHAKE, it can be empty when plain...

	}

	if err := DB.Exec("CREATE EXTENSION IF NOT EXISTS pgcrypto;").Error; err != nil {
		t.Errorf("Failed to create extension pgcrypto, got error %v", err)
	}

	DB.Migrator().DropTable(&Yasuo{})

	if err := DB.AutoMigrate(&Yasuo{}); err != nil {
		t.Fatalf("Failed to migrate for uuid default value, got error: %v", err)
	}

	yasuo := Yasuo{Name: "jinzhu"}
	if err := DB.Create(&yasuo).Error; err != nil {

  public Test testsForEmptyList() {
    return ListTestSuiteBuilder.using(
            new TestStringListGenerator() {
              @Override
              public List<String> create(String[] elements) {
                return emptyList();
              }
            })
        .named("emptyList")
        .withFeatures(CollectionFeature.SERIALIZABLE, CollectionSize.ZERO)

  public Test testsForEmptyList() {
    return ListTestSuiteBuilder.using(
            new TestStringListGenerator() {
              @Override
              public List<String> create(String[] elements) {
                return emptyList();
              }
            })
        .named("emptyList")
        .withFeatures(CollectionFeature.SERIALIZABLE, CollectionSize.ZERO)

    pass


@app.post("/invoices/", callbacks=invoices_callback_router.routes)
def create_invoice(invoice: Invoice, callback_url: Union[HttpUrl, None] = None):
    """
    Create an invoice.

    This will (let's imagine) let the API user (some external developer) create an
    invoice.

    And this path operation will:

    * Send the invoice to the client.
    * Collect the money from the client.