public void TestCPL(byte a, byte result)
        {
            var device = TestUtils.CreateTestDevice();
            var cpu    = device.CPU;
            var alu    = new ALU(cpu);

            cpu.Registers.A = a;
            alu.CPL();
            Assert.Equal(result, cpu.Registers.A);
            Assert.True(cpu.Registers.GetFlag(CpuFlags.SubtractFlag));
            Assert.True(cpu.Registers.GetFlag(CpuFlags.HalfCarryFlag));
        }