public void TestPersonPetStatic1()
 {
     IPersonX p1 = new PersonX();
     IPetX t1 = new PetX();
     t1.Owner = p1;
     Assert.AreEqual(t1.Owner, p1);
     Assert.IsTrue(p1.Pets.Contains(t1));
 }
 public void TestStudentPetStatic2()
 {
     IStudentX s1 = new StudentX();
     IPetX t1 = new PetX();
     s1.Pets.Add(t1);
     Assert.AreEqual(t1.Owner, s1);
     Assert.IsTrue(s1.Pets.Contains(t1));
 }