public void ToStringImplementation()
{
var segment1 = new Segment("E", false);
var segment2 = new Segment("+", true);
var segment3 = new Segment("Number", true);
var production = new Production(segment1, ImmutableArray.Create(segment1, segment2, segment3));
var item0 = new ParseItem(production, 0);
var item1 = new ParseItem(production, 1);
var item2 = new ParseItem(production, 2);
var item3 = new ParseItem(production, 3);
Assert.That(item0.ToString(), Is.EqualTo("[<E> -> \u2022 <E> + Number]"));
Assert.That(item1.ToString(), Is.EqualTo("[<E> -> <E> \u2022 + Number]"));
Assert.That(item2.ToString(), Is.EqualTo("[<E> -> <E> + \u2022 Number]"));
Assert.That(item3.ToString(), Is.EqualTo("[<E> -> <E> + Number \u2022]"));
}