def url_for(book_short_name, chapter=1, overrides={})      
      response = connect!('/audio/path', {
        dam_id: DamId.full( @defaults.merge(overrides.merge({book:book_short_name}) )),
        book_id:    book_short_name,
        chapter_id: chapter,
      })
      file = response.find {|book| book.book_id==book_short_name}.path
      "#{base_url}/#{file}"
    end
def url_for(book_short_name, chapter=1, overrides={})      
      response = connect!('/audio/path', {
        dam_id: DamId.full( @defaults.merge(overrides.merge({book:book_short_name}) )),
        book_id:    book_short_name,
        chapter_id: chapter,
      })
      file = response.find {|book| book.book_id==book_short_name}.path
      "#{base_url}/#{file}"
    end
'fd82d19821647fa4829c7ca160b82e6f'