public async Task <Dictionary <string, long> > MapElapsedTimesByNameAsync(string user)
{
// Whenever a stopwatch is started/restarted, a timestamp (in ticks) is stored.
// We subtract stored time from current time and convert to milliseconds.
return((await _repository.MapTimestampsByNameAsync(user)).ToDictionary(
x => x.Key,
x => (_getTimestamp() - x.Value) / TimeSpan.TicksPerMillisecond));
}