static FbConnectionPoolManager()
        {
            Instance = new FbConnectionPoolManager();
#if !NETSTANDARD1_6
            AppDomain.CurrentDomain.DomainUnload += (sender, e) => Instance.Dispose();
            AppDomain.CurrentDomain.ProcessExit  += (sender, e) => Instance.Dispose();
#endif
        }
 static FbConnectionPoolManager()
 {
     Instance = new FbConnectionPoolManager();
     ShutdownHelper.RegisterPoolCleanup(Instance.Dispose);
 }