old_contents: g.books = [
      ["Pride and Prejudice","http://s3.amazonaws.com/gbbooks/pg1342.txt"],
      ["Alice's Adventures in Wonderland","http://s3.amazonaws.com/gbbooks/pg11.txt"],
      ["Adventures of Huckleberry Finn","http://s3.amazonaws.com/gbbooks/pg76.txt"],
      ["The Importance of Being Earnest","http://s3.amazonaws.com/gbbooks/pg844.txt"],
      ["The Adventures of Tom Sawyer","http://s3.amazonaws.com/gbbooks/pg74.txt"],
      ["A Doll's House","http://s3.amazonaws.com/gbbooks/pg2542.txt"],
      ["Metamorphosis","http://s3.amazonaws.com/gbbooks/pg5200.txt"],
      ["The Yellow Wallpaper","http://s3.amazonaws.com/gbbooks/pg1952.txt"],
      ["A Tale of Two Cities","http://s3.amazonaws.com/gbbooks/pg98.txt"],
      ["Ulysses","http://s3.amazonaws.com/gbbooks/pg4300.txt"],
      ["The Kama Sutra of Vatsyayana","http://s3.amazonaws.com/gbbooks/pg27827.txt"],
      ["The Picture of Dorian Gray","http://s3.amazonaws.com/gbbooks/pg174.txt"],
      ["Frankenstein; Or, The Modern Prometheus","http://s3.amazonaws.com/gbbooks/pg84.txt"],
      ["Grimms' Fairy Tales","http://s3.amazonaws.com/gbbooks/pg2591.txt"],
      ["The Prince","http://s3.amazonaws.com/gbbooks/pg1232.txt"],
      ["The Adventures of Sherlock Holmes","http://s3.amazonaws.com/gbbooks/pg1661.txt"],
      ["A Modest Proposal","http://s3.amazonaws.com/gbbooks/pg1080.txt"],
      ["Moby Dick; Or, The Whale","http://s3.amazonaws.com/gbbooks/pg2701.txt"],
      ["Great Expectations","http://s3.amazonaws.com/gbbooks/pg1400.txt"],
      ["Narrative of the Life of Frederick Douglass, an American Slave","http://s3.amazonaws.com/gbbooks/pg23.txt"],
      ["Leaves of Grass","http://s3.amazonaws.com/gbbooks/pg1322.txt"],
      ["Dracula","http://s3.amazonaws.com/gbbooks/pg345.txt"],
      ["Les Miserables","http://s3.amazonaws.com/gbbooks/pg135.txt"],
      ["Emma","http://s3.amazonaws.com/gbbooks/pg158.txt"],
      ["Steam, Its Generation and Use","http://s3.amazonaws.com/gbbooks/pg22657.txt"],
      ["Beowulf","http://s3.amazonaws.com/gbbooks/pg16328.txt"],
      ["Dubliners","http://s3.amazonaws.com/gbbooks/pg2814.txt"],
      ["Jane Eyre: An Autobiography","http://s3.amazonaws.com/gbbooks/pg1260.txt"],
      ["The Romance of Lust","http://s3.amazonaws.com/gbbooks/pg30254.txt"],
      ["The Divine Comedy","http://s3.amazonaws.com/gbbooks/pg8800.txt"],
  ]
  
new_contents: g.books = [
      ["Pride and Prejudice","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg1342.txt"],
      ["Alice's Adventures in Wonderland","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg11.txt"],
      ["Adventures of Huckleberry Finn","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg76.txt"],
      ["The Importance of Being Earnest","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg844.txt"],
      ["The Adventures of Tom Sawyer","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg74.txt"],
      ["A Doll's House","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg2542.txt"],
      ["Metamorphosis","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg5200.txt"],
      ["The Yellow Wallpaper","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg1952.txt"],
      ["A Tale of Two Cities","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg98.txt"],
      ["Ulysses","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg4300.txt"],
      ["The Kama Sutra of Vatsyayana","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg27827.txt"],
      ["The Picture of Dorian Gray","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg174.txt"],
      ["Frankenstein; Or, The Modern Prometheus","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg84.txt"],
      ["Grimms' Fairy Tales","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg2591.txt"],
      ["The Prince","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg1232.txt"],
      ["The Adventures of Sherlock Holmes","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg1661.txt"],
      ["A Modest Proposal","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg1080.txt"],
      ["Moby Dick; Or, The Whale","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg2701.txt"],
      ["Great Expectations","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg1400.txt"],
      ["Narrative of the Life of Frederick Douglass, an American Slave","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg23.txt"],
      ["Leaves of Grass","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg1322.txt"],
      ["Dracula","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg345.txt"],
      ["Les Miserables","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg135.txt"],
      ["Emma","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg158.txt"],
      ["Steam, Its Generation and Use","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg22657.txt"],
      ["Beowulf","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg16328.txt"],
      ["Dubliners","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg2814.txt"],
      ["Jane Eyre: An Autobiography","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg1260.txt"],
      ["The Romance of Lust","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg30254.txt"],
      ["The Divine Comedy","http://d2yzl2mysmkr1m.cloudfront.net/gbbooks/pg8800.txt"],
  ]
  
subject: use cloud front URL