func NewUpdater(putter storage.Putter, signer crypto.Signer, topic []byte) (feeds.Updater, error) {
	p, err := feeds.NewPutter(putter, signer, topic)
	if err != nil {
		return nil, err
	}
	return &updater{Putter: p}, nil
}
NewUpdater constructs a feed updater
package epochs
import (
	"context"
	"github.com/ethsana/sana/pkg/crypto"
	"github.com/ethsana/sana/pkg/feeds"
	"github.com/ethsana/sana/pkg/storage"
)
var _ feeds.Updater = (*updater)(nil)
type updater struct {
	*feeds.Putter
	last  int64
	epoch feeds.Index
}