public async Task <Adult> RemoveAdultAsync(int adultId)
        {
            Adult adultToRemove = _adults.First(a => a.Id == adultId);

            _adults.Remove(adultToRemove);
            await _fileContext.RemoveAdultAsync(adultId);

            await _fileContext.SaveChangesAsync();

            return(adultToRemove);
        }