if clntHashedPayload != "" && clntHashedPayload != query.Get(xhttp.AmzContentSha256) {
		return ErrContentSHA256Mismatch
	}
	// Verify if security token is correct.
	if token != "" && subtle.ConstantTimeCompare([]byte(token), []byte(cred.SessionToken)) != 1 {
		return ErrInvalidToken
	}

	// Verify finally if signature is same.

	// Get canonical request.

	}
}

// have reports whether the remaining tokens (including the current one) contain the specified token.
func (p *Parser) have(token lex.ScanToken) bool {
	for i := p.inputPos; i < len(p.input); i++ {
		if p.input[i].ScanToken == token {
			return true
		}
	}
	return false
}

// at reports whether the next tokens are as requested.

pkg go/token, const AND_NOT_ASSIGN Token
pkg go/token, const ARROW Token
pkg go/token, const ASSIGN Token
pkg go/token, const BREAK Token
pkg go/token, const CASE Token
pkg go/token, const CHAN Token
pkg go/token, const CHAR Token
pkg go/token, const COLON Token
pkg go/token, const COMMA Token
pkg go/token, const COMMENT Token
pkg go/token, const CONST Token
pkg go/token, const CONTINUE Token

    """
    OAuth2 flow for authentication using a bearer token obtained with an OAuth2 code
    flow. An instance of it would be used as a dependency.
    """

    def __init__(
        self,
        authorizationUrl: str,
        tokenUrl: Annotated[
            str,
            Doc(
                """
                The URL to obtain the OAuth2 token.
                """
            ),
        ],

    name: Add to project
    runs-on: ubuntu-latest
    steps:
      - uses: actions/add-to-project@v1.0.2
        with:
          project-url: https://github.com/orgs/fastapi/projects/2

# 🤚 ⏮️ 👩‍💻

⏮️ 📃 💂‍♂ ⚙️ (❔ 🧢 🔛 🔗 💉 ⚙️) 🤝 *➡ 🛠️ 🔢* `token` `str`:

```Python hl_lines="10"
{!../../docs_src/security/tutorial001.py!}
```

✋️ 👈 🚫 👈 ⚠.

➡️ ⚒ ⚫️ 🤝 👥 ⏮️ 👩‍💻.

## ✍ 👩‍💻 🏷

🥇, ➡️ ✍ Pydantic 👩‍💻 🏷.

🎏 🌌 👥 ⚙️ Pydantic 📣 💪, 👥 💪 ⚙️ ⚫️ 🙆 🙆:

//// tab | 🐍 3️⃣.6️⃣ & 🔛

```Python hl_lines="5  12-16"
{!> ../../docs_src/security/tutorial002.py!}
```

////

from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()

reusable_oauth2 = OAuth2(
    flows={
        "password": {
            "tokenUrl": "token",
            "scopes": {"read:users": "Read the users", "write:users": "Create users"},
        }
    },
    auto_error=False,
)


class User(BaseModel):
    username: str

	args.QuoteEscapeCharacter = defaultQuoteEscapeCharacter
	args.CommentCharacter = defaultCommentCharacter
	args.AllowQuotedRecordDelimiter = false

	for {
		// Read tokens from the XML document in a stream.
		t, err := d.Token()
		if err != nil {
			if err == io.EOF {
				break
			}
			return err
		}

		if se, ok := t.(xml.StartElement); ok {
			tagName := se.Name.Local
			switch tagName {

    TFE_CancellationToken token) {
  return tensorflow::unwrap(cancellation_manager)->DeregisterCallback(token);
}

bool TFE_CancellationManagerTryDeregisterCallback(
    TFE_CancellationManager* cancellation_manager,
    TFE_CancellationToken token) {
  return tensorflow::unwrap(cancellation_manager)->TryDeregisterCallback(token);
}

void TFE_DeleteCancellationManager(

type sender interface {
	msgp.MarshalSizer
	Op() Op
}

type connectReq struct {
	ID    [16]byte
	Host  string
	Time  time.Time
	Token string
}

// addToken will add the token to the connect request.
func (c *connectReq) addToken(fn AuthFn) {
	c.Token = fn()
}

func (connectReq) Op() Op {
	return OpConnect
}

type connectResp struct {
	ID             [16]byte
	Accepted       bool