func (sg *StorageGroup) ExpirationEpoch() uint64 {
	return (*storagegroup.StorageGroup)(sg).
		GetExpirationEpoch()
}
ExpirationEpoch returns last NeoFS epoch number
of the storage group lifetime.
package storagegroup
import (
	"github.com/nspcc-dev/neofs-api-go/pkg"
	"github.com/nspcc-dev/neofs-api-go/pkg/object"
	"github.com/nspcc-dev/neofs-api-go/v2/refs"
	"github.com/nspcc-dev/neofs-api-go/v2/storagegroup"
)
type StorageGroup storagegroup.StorageGroup
func NewFromV2(aV2 *storagegroup.StorageGroup) *StorageGroup {
	return (*StorageGroup)(aV2)
}
func New() *StorageGroup {
	return NewFromV2(new(storagegroup.StorageGroup))
}
func (sg *StorageGroup) ValidationDataSize() uint64 {
	return (*storagegroup.StorageGroup)(sg).
		GetValidationDataSize()
}
func (sg *StorageGroup) SetValidationDataSize(epoch uint64) {
	(*storagegroup.StorageGroup)(sg).
		SetValidationDataSize(epoch)
}
func (sg *StorageGroup) ValidationDataHash() *pkg.Checksum {
	return pkg.NewChecksumFromV2(
		(*storagegroup.StorageGroup)(sg).
			GetValidationHash(),
	)
}
func (sg *StorageGroup) SetValidationDataHash(hash *pkg.Checksum) {
	(*storagegroup.StorageGroup)(sg).
		SetValidationHash(hash.ToV2())
}