	@Test
	void testConvert13to10() {

		Book b;
		
		b = new Book("9780306406157", "", "");
		assertEquals("0306406152", b.getIsbn().isbn10().toString());

		b = new Book("9780596007126", "", "");
		assertEquals("0596007124", b.getIsbn().isbn10().toString());
		
		b = new Book("9781491950357", "", "");
		assertEquals("1491950358", b.getIsbn().isbn10().toString());
	}