public void TestGetNullable01() {
var productions = new HashSet<Production> {
CFGParser.Production("<X> -> <B> <B>"),
CFGParser.Production("<B> -> 'b'"),
CFGParser.Production("<B> -> ε"),
};
var result = (Dictionary<Nonterminal, double>)nullableClass.InvokeStatic("GetNullable", new object[] { productions });
Assert.IsTrue(result.Count == 2);
Helpers.AssertNear(0.5, result[Nonterminal.Of("B")]);
Helpers.AssertNear(0.25, result[Nonterminal.Of("X")]);
}