public void Delete_GivenBookId_RemovesBookFromLibrary() { // Arrange var bookLibrary = new BookLibrary(); bookLibrary.Add("A Tale of Two Cities"); bookLibrary.Add("Fellowship of the Ring"); bookLibrary.Add("Pride and Prejudice and Zombies"); // Act bookLibrary.Delete(1); // Assert Assert.Throws <KeyNotFoundException>(() => bookLibrary.Get(1)); }