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: uuid.go
    path of file: ./repos/tegola/vendor/github.com/jackc/pgtype/ext/gofrs-uuid
    
    the code of the file until where you have to start completion: package uuid

import (
	"database/sql/driver"
	"errors"
	"fmt"

	"github.com/gofrs/uuid"
	"github.com/jackc/pgtype"
)

var errUndefined = errors.New("cannot encod
    
func (src UUID) MarshalJSON() ([]byte, error) {
	switch src.Status {
	case pgtype.Present:
		return []byte(`"` + src.UUID.String() + `"`), nil
	case pgtype.Null:
		return []byte("null"), nil
	case pgtype.Undefined:
		return nil, errUndefined
	}

	return nil, errBadStatus
}