public void IfNotOptimalEnumeratesAnyway()
        {
            var db = new MockDb(9);

            foreach (var(key, value) in db.EnumerateOptimally(db.OptimalToken))
            {
                db.EvaluateNext.Should().BeTrue();
            }
        }
        public void OptimallyEnumeratesEveryTen()
        {
            var db = new MockDb(100);

            foreach (var(key, value) in db.EnumerateOptimally(db.OptimalToken))
            {
                db.EvaluateNext.Should().BeFalse();
            }
        }