public void Free() { var ram = new Ram(2, 1); var pcb = new ProcessContextBlock { Id = 1 }; var frame = ram.Allocate(pcb); Assert.That(frame, Is.Not.Null); frame = ram.Allocate(pcb); Assert.That(frame, Is.Not.Null); ram.Free(frame); frame = ram.Allocate(pcb); Assert.That(frame, Is.Not.Null); }