func (h HandlerFuncs) OnAdd(obj ClusterObject) {
	if h.AddFunc != nil {
		h.AddFunc(obj)
	}
}
OnAdd calls AddFunc if it's not nil.
package differ
import (
	"fmt"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/util/sets"
	"sigs.k8s.io/cluster-api-provider-nested/virtualcluster/pkg/syncer/conversion"
)
type HandlerFuncs struct {
	AddFunc    func(obj ClusterObject)
	DeleteFunc func(obj ClusterObject)
	UpdateFunc func(obj1, obj2 ClusterObject)
}