public void StatePromote()
{
// enemy king needed for extended calculation of promotion
State o = new State("wpb7 bka8");
Assert.Equal(2, o.Live.Count);
Assert.Equal("P", o.Live[0].Sym);
Assert.Equal("k", o.Live[1].Sym);
o.Promote(new List <Ret>(), 'Q', 2, 7, 2, 8);
Assert.Equal(2, o.Live.Count);
Assert.Equal("k", o.Live[0].Sym);
Assert.Equal("Q", o.Live[1].Sym);
}
