You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: validator_custom.go
    path of file: ./repos/openyurt/pkg/yurtmanager/webhook/builder
    
    the code of the file until where you have to start completion: /*
Copyright 2023 The OpenYurt Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

	http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package builder

import (
	"context"
	"errors"
	"fmt"
	"net/http"

	v1 "k8s.io/api/admission/v1"
	apierrors "k8s.io/apimachinery
    
func (h *validatorForType) Handle(ctx context.Context, req admission.Request) admission.Response {
	if h.validator == nil {
		panic("validator should never be nil")
	}
	if h.object == nil {
		panic("object should never be nil")
	}

	// Get the object in the request
	obj := h.object.DeepCopyObject()

	var err error
	switch req.Operation {
	case v1.Create:
		if err := h.decoder.Decode(req, obj); err != nil {
			return admission.Errored(http.StatusBadRequest, err)
		}

		err = h.validator.ValidateCreate(ctx, obj, req)
	case v1.Update:
		oldObj := obj.DeepCopyObject()
		if err := h.decoder.DecodeRaw(req.Object, obj); err != nil {
			return admission.Errored(http.StatusBadRequest, err)
		}
		if err := h.decoder.DecodeRaw(req.OldObject, oldObj); err != nil {
			return admission.Errored(http.StatusBadRequest, err)
		}

		err = h.validator.ValidateUpdate(ctx, oldObj, obj, req)
	case v1.Delete:
		// In reference to PR: https://github.com/kubernetes/kubernetes/pull/76346
		// OldObject contains the object being deleted
		if err := h.decoder.DecodeRaw(req.OldObject, obj); err != nil {
			return admission.Errored(http.StatusBadRequest, err)
		}

		err = h.validator.ValidateDelete(ctx, obj, req)
	default:
		return admission.Errored(http.StatusBadRequest, fmt.Errorf("unknown operation request %q", req.Operation))
	}

	// Check the error message first.
	if err != nil {
		var apiStatus apierrors.APIStatus
		if errors.As(err, &apiStatus) {
			return validationResponseFromStatus(false, apiStatus.Status())
		}
		return admission.Denied(err.Error())
	}

	// Return allowed if everything succeeded.
	return admission.Allowed("")
}