@Test
public void print_itself() throws Exception {
Book book = aCookingBook().costing(5.0d).build();
assertThat(book.toString(), is("Book{name='book name', type='COOKING', price=5.0}"));
}
@Test
public void be_named() throws Exception {
Book book = aCookingBook().build();
assertThat(book.name(), is("book name"));
}