public void AddBranch()
 {
     Assert.That(service.Add("east"), Is.EqualTo(1));
     Assert.That(service.BranchNames(), Is.EqualTo(new List <string> {
         "east"
     }));
 }
        public void PersistentStorage()
        {
            service.Add("east");
            var secondService = new BranchService();

            Assert.That(secondService.BranchNames(), Is.EqualTo(new List <string> {
                "east"
            }));
        }