public void DrawStatusBar_HappyPath_FillsLineAtBottom()
        {
            CharInfo[] actualBuffer = new CharInfo[4];

            // Arrange

            var screenBufferMock = new Mock <IScreenBuffer>();

            screenBufferMock.SetupGet(sb => sb.Width).Returns(2);
            screenBufferMock.SetupGet(sb => sb.Height).Returns(2);
            screenBufferMock.Setup(sb => sb.Render(It.IsAny <Action <CharInfo[]> >()))
            .Callback <Action <CharInfo[]> >(a => a(actualBuffer));

            // Act

            var screenController = new ScreenController(screenBufferMock.Object);

            screenController.DrawStatusBar();

            // Assert

            const int attribute = 1 << 4 | 15;

            actualBuffer[2].AsciiChar.Should().Be('\0');
            actualBuffer[2].Attributes.Should().Be(attribute);

            actualBuffer[3].AsciiChar.Should().Be('\0');
            actualBuffer[3].Attributes.Should().Be(attribute);
        }