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);
        }