SatisfactionExpr

void TestExpr() {
        Student p("ivan"s, 37);
        SatisfactionSupervisor sup{103, 107};
        p.SetObserver(&sup);
       ASSERT_EQUAL(p.GetDanceCount(), 0);
        ASSERT_EQUAL(p.GetSatisfaction(), 100);
        p.Dance();
        ASSERT_EQUAL(p.GetDanceCount(), 1);
        ASSERT_EQUAL(p.GetSatisfaction(), 101);
    }