resp(mid.closed)
		mid.respMu.Unlock()
	case debugBlockInboundMessages:
		c.connMu.Lock()
		block := (<-chan struct{})(args[0].(chan struct{}))
		c.blockMessages.Store(&block)
		c.connMu.Unlock()
	}
}

// wsWriter writes websocket messages.
type wsWriter struct {
	tmp [ws.MaxHeaderSize]byte
}

// writeMessage writes a message to w without allocations.

	"istio.io/istio/pkg/maps"
)

// ConfigWriter is a writer for processing responses from the Ztunnel Admin config_dump endpoint
type ConfigWriter struct {
	Stdout      io.Writer
	ztunnelDump *ZtunnelDump
	FullDump    []byte
}

type rawDump struct {
	Services      json.RawMessage          `json:"services"`
	Workloads     json.RawMessage          `json:"workloads"`

// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package http

import (
	"bytes"
	"io"
)

// RequestRecorder - records the
// of a given io.Reader
type RequestRecorder struct {
	// Data source to record
	io.Reader
	// Response body should be logged
	LogBody bool

	// internal recording buffer
	buf bytes.Buffer
	// total bytes read including header size
	bytesRead int
}

// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package event

import (
	"encoding/xml"
	"strings"
)

// ARN - SQS resource name representation.
type ARN struct {
	TargetID
	region string
}

// String - returns string representation.
func (arn ARN) String() string {
	if arn.TargetID.ID == "" && arn.TargetID.Name == "" && arn.region == "" {
		return ""
	}

// limitations under the License.

package testutil

import (
	"bytes"
	"regexp"
	"strings"
	"testing"

	"github.com/spf13/cobra"

	"istio.io/istio/pilot/test/util"
)

type TestCase struct {
	Args []string

	// Typically use one of the three
	ExpectedOutput string         // Expected constant output
	ExpectedRegexp *regexp.Regexp // Expected regexp output

)

func writeErrorResponse(w http.ResponseWriter, err error) {
	w.WriteHeader(http.StatusBadRequest)
	json.NewEncoder(w).Encode(map[string]string{
		"reason": fmt.Sprintf("%v", err),
	})
}

type Resp struct {
	User               string                 `json:"user"`
	MaxValiditySeconds int                    `json:"maxValiditySeconds"`
	Claims             map[string]interface{} `json:"claims"`
}

	tokenWaitBackoff = time.Second
)

func init() {
	scheme = runtime.NewScheme()
	utilruntime.Must(v1.AddToScheme(scheme))
	opt := json.SerializerOptions{
		Yaml:   true,
		Pretty: false,
		Strict: false,
	}
	yamlSerializer := json.NewSerializerWithOptions(json.DefaultMetaFactory, scheme, scheme, opt)
	codec = versioning.NewDefaultingCodecForScheme(
		scheme,
		yamlSerializer,
		yamlSerializer,

package target

import (
	"sync"
	"sync/atomic"
)

// Inspired from Golang sync.Once but it is only marked
// initialized when the provided function returns nil.

type lazyInit struct {
	done uint32
	m    sync.Mutex
}

func (l *lazyInit) Do(f func() error) error {
	if atomic.LoadUint32(&l.done) == 0 {
		return l.doSlow(f)
	}
	return nil
}

// Constants for target types
const (
	_ TargetType = iota
	TargetConsole
	TargetHTTP
	TargetKafka
)

// TargetStats contains statistics for a target.
type TargetStats struct {
	// QueueLength is the queue length if any messages are queued.
	QueueLength int

	// TotalMessages is the total number of messages sent in the lifetime of the target
	TotalMessages int64

<div class="screenshot">
<img src="/img/tutorial/header-param-models/image01.png">
</div>

## Forbid Extra Headers

In some special use cases (probably not very common), you might want to **restrict** the headers that you want to receive.

You can use Pydantic's model configuration to `forbid` any `extra` fields:

//// tab | Python 3.10+

```Python hl_lines="10"