public void ContactsSearchGroup() { Contacts contacts = new Contacts(); string name1 ="family"; string name2 ="work"; string name3 ="other"; Group group1 = new Group() { Name = name1 }; Group group2 = new Group() { Name = name2 }; Group group3 = new Group() { Name = name3 }; contacts.AddGroup(group1); contacts.AddGroup(group2); contacts.AddGroup(group3); var res = contacts.SearchGroup("work"); Assert.AreEqual(1, res.Count); }