authString:    "NoV2Prefix",
			expectedError: ErrSignatureVersionNotSupported,
		},
		// Test case - 3.
		// Test case with missing parts in the Auth string.
		// below is the correct format of V2 Authorization header.
		// Authorization = "AWS" + " " + AWSAccessKeyId + ":" + Signature
		{
			authString:    signV2Algorithm,
			expectedError: ErrMissingFields,
		},
		// Test case - 4.
		// Test case with signature part missing.

          @Throws(IOException::class)
          override fun authenticate(
            route: Route?,
            response: Response,
          ): Request? {
            if (response.request.header("Authorization") != null) {
              return null // Give up, we've already attempted to authenticate.
            }

            println("Authenticating for response: $response")

    return {"scheme": credentials.scheme, "credentials": credentials.credentials}


client = TestClient(app)


def test_security_http_digest():
    response = client.get("/users/me", headers={"Authorization": "Digest foobar"})
    assert response.status_code == 200, response.text
    assert response.json() == {"scheme": "Digest", "credentials": "foobar"}


def test_security_http_digest_no_credentials():

    assert response.headers["WWW-Authenticate"] == 'Basic realm="simple"'


def test_security_http_basic_invalid_credentials():
    response = client.get(
        "/users/me", headers={"Authorization": "Basic notabase64token"}
    )
    assert response.status_code == 401, response.text
    assert response.headers["WWW-Authenticate"] == 'Basic realm="simple"'

* 🕸 🏪 👈 🤝 🍕 👱.
* 👩‍💻 🖊 🕸 🚶 ➕1️⃣ 📄 🕸 🕸 📱.
* 🕸 💪 ☕ 🌅 💽 ⚪️➡️ 🛠️.
    * ✋️ ⚫️ 💪 🤝 👈 🎯 🔗.
    * , 🔓 ⏮️ 👆 🛠️, ⚫️ 📨 🎚 `Authorization` ⏮️ 💲 `Bearer ` ➕ 🤝.
    * 🚥 🤝 🔌 `foobar`, 🎚 `Authorization` 🎚 🔜: `Bearer foobar`.

## **FastAPI**'Ⓜ `OAuth2PasswordBearer`

**FastAPI** 🚚 📚 🧰, 🎏 🎚 ⚛, 🛠️ 👫 💂‍♂ ⚒.

    assert response.headers["WWW-Authenticate"] == "Basic"


def test_security_http_basic_invalid_credentials():
    response = client.get(
        "/users/me", headers={"Authorization": "Basic notabase64token"}
    )
    assert response.status_code == 401, response.text
    assert response.headers["WWW-Authenticate"] == "Basic"
    assert response.json() == {"detail": "Invalid authentication credentials"}

			return false, errNotConnected
		}
		return false, err
	}
	tokens := strings.Fields(target.args.AuthToken)
	switch len(tokens) {
	case 2:
		req.Header.Set("Authorization", target.args.AuthToken)
	case 1:
		req.Header.Set("Authorization", "Bearer "+target.args.AuthToken)
	}

	resp, err := target.httpClient.Do(req)
	if err != nil {
		if xnet.IsNetworkOrHostDown(err, true) {
			return false, errNotConnected

    * But it needs authentication for that specific endpoint.
    * So, to authenticate with our API, it sends a header `Authorization` with a value of `Bearer ` plus the token.
    * If the token contains `foobar`, the content of the `Authorization` header would be: `Bearer foobar`.

## **FastAPI**'s `OAuth2PasswordBearer`

    assert response.json() == {"msg": "Create an account first"}


def test_security_http_basic_invalid_credentials():
    response = client.get(
        "/users/me", headers={"Authorization": "Basic notabase64token"}
    )
    assert response.status_code == 401, response.text
    assert response.headers["WWW-Authenticate"] == "Basic"
    assert response.json() == {"detail": "Invalid authentication credentials"}

public final class Authenticate {
  private final OkHttpClient client;

  public Authenticate() {
    client = new OkHttpClient.Builder()
        .authenticator((route, response) -> {
          if (response.request().header("Authorization") != null) {
            return null; // Give up, we've already attempted to authenticate.
          }

          System.out.println("Authenticating for response: " + response);