public void ProgramRepositoryClears()
{
var sut = new ProgramRepository();
sut.SetProgramLine(new ProgramLine(30, new List <IToken> {
new Token("X")
}));
sut.SetProgramLine(new ProgramLine(10, new List <IToken> {
new Token("X")
}));
sut.SetProgramLine(new ProgramLine(20, new List <IToken> {
new Token("X")
}));
sut.SetProgramLine(new ProgramLine(50, new List <IToken> {
new Token("X")
}));
sut.SetProgramLine(new ProgramLine(40, new List <IToken> {
new Token("X")
}));
Assert.IsNotNull(sut.GetFirstLine());
sut.Clear();
Assert.IsNull(sut.GetFirstLine());
}