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: notifications.go
    path of file: ./repos/storj/storagenode/storagenodedb
    
    the code of the file until where you have to start completion: // Copyright (C) 2019 Storj Labs, Inc.
// See LICENSE for copying information.

package storagenodedb

import (
	"context"
	"time"

	"github.com/zeebo/errs"

	"st
    
func (db *notificationDB) UnreadAmount(ctx context.Context) (_ int, err error) {
	defer mon.Task()(&ctx)(&err)
	var amount int

	query := `
		SELECT
			COUNT(id)
		FROM 
			notifications
		WHERE 
			read_at IS NULL
	`

	err = db.QueryRowContext(ctx, query).Scan(&amount)
	if err != nil {
		return 0, ErrNotificationsDB.Wrap(err)
	}

	return amount, nil
}