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: gss_enc_request.go
    path of file: ./repos/tegola/vendor/github.com/jackc/pgproto3/v2
    
    the code of the file until where you have to start completion: package pgproto3

import (
	"encoding/binary"
	"encoding/json"
	"errors"

	"github.com/jackc/pgio"
)

const gssEncReqNumber = 80877104

type GSSEncRequest struct {
}

// Frontend identifies this message as sendable by a PostgreSQL frontend.
func (*GSSEncRequest) Fro
    
func (dst *GSSEncRequest) Decode(src []byte) error {
	if len(src) < 4 {
		return errors.New("gss encoding request too short")
	}

	requestCode := binary.BigEndian.Uint32(src)

	if requestCode != gssEncReqNumber {
		return errors.New("bad gss encoding request code")
	}

	return nil
}