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: ipns.go
    path of file: ./repos/sealer/vendor/github.com/ipfs/go-ipns
    
    the code of the file until where you have to start completion: package ipns

import (
	"bytes"
	"fmt"
	"sort"
	"time"

	"github.com/pkg/errors"

	"github.com/ipld/go-ipld-prime"
	_ "github.com/ipld/go-ipld-prime/codec/dagcbor" // used to import the DagCbor encoder/decoder
	ipldcodec "github.com/ipld/go-ipld-prime/multicodec"
	"github.com/ipld/go-ipld-prime/node/basic"

	"github.com/multiformats/go-multicodec"

	"github.com/gogo/protobuf/proto"

	pb "github.com/ipfs/go-ipns/pb"

	u "github.com/ipfs/go-ipfs-util"
	ic "github.com/libp2p/go-libp2p-core/crypto"
	peer "github.com/libp2p/go-libp2p-core/peer"
)

const (
	validity     = "Validity"
	validityType = "ValidityType"
	value        = "Value"
	sequ
    
func Compare(a, b *pb.IpnsEntry) (int, error) {
	aHasV2Sig := a.GetSignatureV2() != nil
	bHasV2Sig := b.GetSignatureV2() != nil

	// Having a newer signature version is better than an older signature version
	if aHasV2Sig && !bHasV2Sig {
		return 1, nil
	} else if !aHasV2Sig && bHasV2Sig {
		return -1, nil
	}

	as := a.GetSequence()
	bs := b.GetSequence()

	if as > bs {
		return 1, nil
	} else if as < bs {
		return -1, nil
	}

	at, err := u.ParseRFC3339(string(a.GetValidity()))
	if err != nil {
		return 0, err
	}

	bt, err := u.ParseRFC3339(string(b.GetValidity()))
	if err != nil {
		return 0, err
	}

	if at.After(bt) {
		return 1, nil
	} else if bt.After(at) {
		return -1, nil
	}

	return 0, nil
}