def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

        self.sut = PasiekaFitness()
        self.rule = Rule(Symbol(hash('A')), Symbol(hash('B')), Symbol(hash('C')))

        self.statistics_mock = create_autospec(GrammarStatistics)
class TestPasiekaFitness(unittest.TestCase):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

        self.sut = PasiekaFitness()
        self.rule = Rule(Symbol(hash('A')), Symbol(hash('B')), Symbol(hash('C')))

        self.statistics_mock = create_autospec(GrammarStatistics)

    def test_fitness_should_be_calculated_properly(self):
        rule_info = PasiekaRuleInfo()
        rule_info.rule_usage = 4

        left_side_info = PasiekaLeftSideInfo()
        left_side_info.left_side_usage = 5

        self.statistics_mock.get_rule_statistics.return_value = rule_info, left_side_info
        assert_that(self.sut.calculate(self.statistics_mock, self.rule), is_(equal_to(4)))