The C<many_to_many> relationship is optional, but it makes it
easier to map a book to its collection of authors. Without
-it, we would have to "walk" though the C<book_author> table as in
+it, we would have to "walk" through the C<book_author> table as in
C<$book-E<gt>book_author-E<gt>first-E<gt>author-E<gt>last_name> (we
will see examples on how to use DBIx::Class objects in your code soon,
but note that because C<$book-E<gt>book_author> can return multiple