public async Task <int> Handle(AddOrUpdateTimeZoneCommand command)
 {
     command.TimeZone.Name.ThrowIfNullOrEmpty("Invalid time zone name parameter", nameof(command.TimeZone.Name));
     command.UserId.ThrowIfNotPositiveNonZeroInt("Invalid user id parameter", nameof(command.UserId));
     return(await _timeZoneRepository.AddOrUpdateTimeZoneAsync(command.TimeZone, command.UserId).ConfigureAwait(false));
 }