return c.c
}

var _ Singleton[any] = &collectionAdapter[any]{}

func NewSingleton[O any](hf TransformationEmpty[O], opts ...CollectionOption) Singleton[O] {
	// dummyCollection provides a trivial collection implementation that always provides a single dummyValue.
	// This is an internal construct exclusively for implementing the "Singleton" pattern.
	// This is so we can represent a singleton (a func() *O) as a collection (a func(I) *O).

// See the License for the specific language governing permissions and
// limitations under the License.

// Provides utility methods to generate X.509 certificates with different
// options. This implementation is Largely inspired from
// https://golang.org/src/crypto/tls/generate_cert.go.

package util

import (
	"crypto"
	"crypto/ecdsa"
	"crypto/elliptic"
	"crypto/rand"
	"crypto/rsa"
	"crypto/x509"

	Analyzer
	RelevantSubset(kinds sets.Set[config.GroupVersionKind]) CombinedAnalyzer
	RemoveSkipped(schemas collection.Schemas) []string
	AnalyzerNames() []string
}

// InternalCombinedAnalyzer is an implementation of CombinedAnalyzer, a special analyzer that combines multiple analyzers into one
type InternalCombinedAnalyzer struct {
	name      string
	analyzers []Analyzer
}

// Combine multiple analyzers into a single one.

	ValidationErrorCode     = 126
)

// DNS ports
const (
	IstioAgentDNSListenerPort = "15053"
)

// type of iptables operation/command to run, as an enum
// the implementation will choose the correct underlying binary,
// so callers should just use these enums to indicate what they want to do.
type IptablesCmd int

const (
	IPTables        IptablesCmd = iota

  // +optional
  optional k8s.io.apimachinery.pkg.util.intstr.IntOrString maxUnavailable = 3;

  // UnhealthyPodEvictionPolicy defines the criteria for when unhealthy pods
  // should be considered for eviction. Current implementation considers healthy pods,
  // as pods that have status.conditions item with type="Ready",status="True".
  //
  // Valid policies are IfHealthyBudget and AlwaysAllow.

| HOST_PROBE_SNAT_IPV6 | "fd16:9254:7127:1337:ffff:ffff:ffff:ffff" | IPv6 link local ranges are designed to be collision-resistant by default, and so this probably never needs to be overridden |

## Sidecar Mode Implementation Details

Istio CNI injection is currently based on the same Pod annotations used in init-container/inject mode.

### Selection API

- plugin config "exclude namespaces" applies first
- ambient is enabled if:

func NewCollection[I, O any](c Collection[I], hf TransformationSingle[I, O], opts ...CollectionOption) Collection[O] {
	// For implementation simplicity, represent TransformationSingle as a TransformationMulti so we can share an implementation.
	hm := func(ctx HandlerContext, i I) []O {
		res := hf(ctx, i)
		if res == nil {
			return nil
		}
		return []O{*res}
	}

)

// DeploymentController implements a controller that materializes a Gateway into an in cluster gateway proxy
// to serve requests from. This is implemented with a Deployment and Service today.
// The implementation makes a few non-obvious choices - namely using Server Side Apply from go templates
// and not using controller-runtime.
//
// controller-runtime has a number of constraints that make it inappropriate for usage here, despite this

  //
  // * Kubernetes-defined prefixed names:
  //   * 'kubernetes.io/h2c' - HTTP/2 over cleartext as described in https://www.rfc-editor.org/rfc/rfc7540
  //
  // * Other protocols should use implementation-defined prefixed names such as
  // mycompany.com/my-custom-protocol.
  // +optional
  optional string appProtocol = 4;
}

// EndpointSlice represents a subset of the endpoints that implement a service.

	// DisableAutomountSAToken indicates to opt out of auto mounting ServiceAccount's API credentials
	DisableAutomountSAToken bool

	// Ports for this application. Port numbers may or may not be used, depending
	// on the implementation.
	Ports Ports

	// ServiceAnnotations is annotations on service object.
	ServiceAnnotations map[string]string

	// ServiceLabels is the labels on service object.
	ServiceLabels map[string]string