public void First_generic_verse()
    {
        var expected =
            "99 bottles of beer on the wall, 99 bottles of beer.\n" +
            "Take one down and pass it around, 98 bottles of beer on the wall.\n" +
            "";

        Assert.Equal(expected, BeerSong.Verse(99));
    }
    public void Verse_0()
    {
        var expected =
            "No more bottles of beer on the wall, no more bottles of beer.\n" +
            "Go to the store and buy some more, 99 bottles of beer on the wall.\n" +
            "";

        Assert.Equal(expected, BeerSong.Verse(0));
    }
    public void Verse_2()
    {
        var expected =
            "2 bottles of beer on the wall, 2 bottles of beer.\n" +
            "Take one down and pass it around, 1 bottle of beer on the wall.\n" +
            "";

        Assert.Equal(expected, BeerSong.Verse(2));
    }
    public void Verse_1()
    {
        var expected =
            "1 bottle of beer on the wall, 1 bottle of beer.\n" +
            "Take it down and pass it around, no more bottles of beer on the wall.\n" +
            "";

        Assert.Equal(expected, BeerSong.Verse(1));
    }
    public void Last_generic_verse()
    {
        var expected =
            "3 bottles of beer on the wall, 3 bottles of beer.\n" +
            "Take one down and pass it around, 2 bottles of beer on the wall.\n" +
            "";

        Assert.Equal(expected, BeerSong.Verse(3));
    }