public void Run()
 {
     while (true)
     {
         Thread.Sleep(TimeSpan.FromSeconds(rand.Next(1, 5)));
         Console.WriteLine($"Reader {Id} wants to read.");
         db.AcquireReadLock(Id);
         Console.WriteLine($"Reader {Id} is reading ...");
         Thread.Sleep(TimeSpan.FromSeconds(rand.Next(1, 5)));
         db.ReleaseReadLock(Id);
     }
 }