Get an iterator of pages.

        :param int pages: optional limit to number of pages
        :return: iter of this and subsequent pages

def iter(self, pages=None):
        '''Get an iterator of pages.

        :param int pages: optional limit to number of pages
        :return: iter of this and subsequent pages
        '''
        i = self._pages()
        if pages is not None:
            i = itertools.islice(i, pages)
        return i