class TestPerson(unittest.TestCase):

    def setUp(self):
        self.person = Person(15, 60, 170)

    def it_gain_weight(self):
        self.person.gain_weight(5)
        self.person.weight |should| equal_to(65)

    def it_lose_weight(self):
        self.person.lose_weight(2)
        self.person.weight |should| equal_to(58)

    def it_get_old_6_years_and_check_its_height(self):
        self.person.get_old(6)
        self.person.height |should| equal_to(179)
        self.person.old |should| equal_to(21)

    def it_stop_to_get_height_at_21_years(self):
        self.person.get_old(10)
        self.person.height |should| equal_to(179)
        self.person.old |should| equal_to(25)
 def setUp(self):
     self.person = Person(15, 60, 170)