public void FirstBorrowedBookBuilderTest()
        {
            var person = new Person(0, "kasper", "cisewski");
            BorrowedBookListBuilder borrowedBookListBuilder = new BorrowedBookListBuilder();
            var expected = "";
            var actual   = borrowedBookListBuilder.BuildBorrowedBookList(person);

            Assert.AreEqual(expected, actual);
        }
        public void SecondBorrwerBookBuilderTest()
        {
            var person = new Person(0, "kasper", "cisewski");
            var book   = new Book("znak", "gulczynski", "1234567891234");

            person.BorrowedBooks.Add(book);

            BorrowedBookListBuilder borrowedBookListBuilder = new BorrowedBookListBuilder();
            var expected = "znak - gulczynski - 1234567891234\r\n";
            var actual   = borrowedBookListBuilder.BuildBorrowedBookList(person);

            Assert.AreEqual(expected, actual);
        }