export function getTimestamp(date: Date | null = null) {
    const now = date || new Date();
    return now.getFullYear()
            + '-'
            + (now.getMonth() + 1)
            + '-' + now.getDate()
            + ' ' + now.getHours()
            + ':' + now.getMinutes()
            + ':' + now.getSeconds();
}