After this, the client and the server have an **encrypted TCP connection**, this is what TLS provides. And then they can use that connection to start the actual **HTTP communication**.

```

### More technical details { #more-technical-details }

You might have noticed that `await` can only be used inside of functions defined with `async def`.

But at the same time, functions defined with `async def` have to be "awaited". So, functions with `async def` can only be called inside of functions defined with `async def` too.

So, about the egg and the chicken, how do you call the first `async` function?

Para eso, **FastAPI** proporciona una función `jsonable_encoder()`.

## Usando el `jsonable_encoder` { #using-the-jsonable-encoder }

Imaginemos que tienes una base de datos `fake_db` que solo recibe datos compatibles con JSON.

Por ejemplo, no recibe objetos `datetime`, ya que no son compatibles con JSON.

	// if object upload fails stop the test.
	if err != nil {
		t.Fatalf("Error uploading object: <ERROR> %v", err)
	}

	// initialize httptest Recorder, this records any mutations to response writer inside the handler.
	rec := httptest.NewRecorder()
	// construct HTTP request for DELETE bucket.

	if !reflect.DeepEqual(lc.Keys(), []string{"key1"}) {
		t.Fatalf("value differs from expected")
	}

	if lc.Resize(0) != 0 {
		t.Fatalf("evicted count differs from expected")
	}
	if lc.Resize(2) != 0 {
		t.Fatalf("evicted count differs from expected")
	}
	lc.Add("key2", "val2")
	if lc.Resize(1) != 1 {
		t.Fatalf("evicted count differs from expected")
	}
}

func TestLRUEdgeCases(t *testing.T) {

The `TestClient` does some magic inside to call the asynchronous FastAPI application in your normal `def` test functions, using standard pytest. But that magic doesn't work anymore when we're using it inside asynchronous functions. By running our tests asynchronously, we can no longer use the `TestClient` inside our test functions.

        assertEquals(
                "One or more required plugin parameters are invalid/missing for 'goalPrefix:goal'" + LS
                        + LS + "[0] Inside the definition for plugin 'artifactId', specify the following:"
                        + LS
                        + LS + "<configuration>"
                        + LS + "  ..."
                        + LS + "  <toAddresses>"

	for i, testCase := range testCases {
		// obtain the put bucket policy request body.
		// initialize HTTP NewRecorder, this records any mutations to response writer inside the handler.
		recV4 := httptest.NewRecorder()
		// construct HTTP request for PUT bucket policy endpoint.
		reqV4, err := newTestSignedRequestV4(http.MethodPut, getPutPolicyURL("", testCase.bucketName),

{* ../../docs_src/query_params_str_validations/tutorial002_an_py310.py hl[9] *}

Notice that the default value is still `None`, so the parameter is still optional.

Then you could want to have **a single container** with a **process manager** starting **several worker processes** inside.

---

The main point is, **none** of these are **rules written in stone** that you have to blindly follow. You can use these ideas to **evaluate your own use case** and decide what is the best approach for your system, checking out how to manage the concepts of:

* Security - HTTPS
* Running on startup