public void _04_CloseAllSessionsTest()
        {
            using (IPkcs11 pkcs11 = Settings.Factories.Pkcs11Factory.CreatePkcs11(Settings.Factories, Settings.Pkcs11LibraryPath, Settings.AppType))
            {
                // Find first slot with token present
                ISlot slot = Helpers.GetUsableSlot(pkcs11);

                // Open RO (read-only) session
                ISession session = slot.OpenSession(SessionType.ReadOnly);

                // Do something interesting in RO session
                Assert.IsNotNull(session);

                // All sessions can be closed with CloseAllSessions method of Slot class.
                slot.CloseAllSessions();
            }
        }