public void SavePhoneBookTest()
{
PhoneBookCreator creator = new PhoneBookCreator();
IPhoneBook book = creator.CreateNewPhoneBook();
string filePath = "File.bin";
book.CreatePhoneBookEntry("Gosho", "Goshov");
Assert.IsFalse(File.Exists(filePath));
creator.SavePhoneBook(filePath, book);
Assert.IsTrue(File.Exists(filePath));
IPhoneBook loadingBook = creator.LoadPhoneBook(filePath);
Assert.IsNotEmpty(loadingBook.GetPhoneBookEntriesSortedByFirstName());
Assert.IsTrue(loadingBook.GetPhoneBookEntriesSortedByFirstName().Count == 1);
Assert.AreEqual("Gosho", loadingBook.GetPhoneBookEntriesSortedByFirstName()[0].FirstName);
File.Delete(filePath);
}