func TestStampMarshalling(t *testing.T) {
	sExp := postagetesting.MustNewStamp()
	buf, _ := sExp.MarshalBinary()
	if len(buf) != postage.StampSize {
		t.Fatalf("invalid length for serialised stamp. expected %d, got  %d", postage.StampSize, len(buf))
	}
	s := postage.NewStamp(nil, nil, nil, nil)
	if err := s.UnmarshalBinary(buf); err != nil {
		t.Fatalf("unexpected error unmarshalling stamp: %v", err)
	}
	compareStamps(t, sExp, s)
}
TestStampMarshalling tests the idempotence  of binary marshal/unmarshals for Stamps.
package postage_test
import (
	"bytes"
	"math/big"
	"testing"
	"github.com/ethsana/sana/pkg/crypto"
	"github.com/ethsana/sana/pkg/postage"
	"github.com/ethsana/sana/pkg/postage/batchstore/mock"
	postagetesting "github.com/ethsana/sana/pkg/postage/testing"
	chunktesting "github.com/ethsana/sana/pkg/storage/testing"
)