text: let authors = [
    {
      name: 'Robert Martin',
      id: "afa51ab0-344d-11e9-a414-719c6709cf3e",
      born: 1952,
    },
    {
      name: 'Martin Fowler',
      id: "afa5b6f0-344d-11e9-a414-719c6709cf3e",
      born: 1963
    },
    {
      name: 'Fyodor Dostoevsky',
      id: "afa5b6f1-344d-11e9-a414-719c6709cf3e",
      born: 1821
    },
    { 
      name: 'Joshua Kerievsky', // birthyear not known
      id: "afa5b6f2-344d-11e9-a414-719c6709cf3e",
    },
    { 
      name: 'Sandi Metz', // birthyear not known
      id: "afa5b6f3-344d-11e9-a414-719c6709cf3e",
    },
  ]
  
  /*
   * It would be more sensible to assosiate book and the author by saving 
   * the author id instead of the name to the book.
   * For simplicity we however save the author name.
  */
  
  let books = [
    {
      title: 'Clean Code',
      published: 2008,
      author: 'Robert Martin',
      id: "afa5b6f4-344d-11e9-a414-719c6709cf3e",
      genres: ['refactoring']
    },
    {
      title: 'Agile software development',
      published: 2002,
      author: 'Robert Martin',
      id: "afa5b6f5-344d-11e9-a414-719c6709cf3e",
      genres: ['agile', 'patterns', 'design']
    },
    {
      title: 'Refactoring, edition 2',
      published: 2018,
      author: 'Martin Fowler',
      id: "afa5de00-344d-11e9-a414-719c6709cf3e",
      genres: ['refactoring']
    },
    {
      title: 'Refactoring to patterns',
      published: 2008,
      author: 'Joshua Kerievsky',
      id: "afa5de01-344d-11e9-a414-719c6709cf3e",
      genres: ['refactoring', 'patterns']
    },  
    {
      title: 'Practical Object-Oriented Design, An Agile Primer Using Ruby',
      published: 2012,
      author: 'Sandi Metz',
      id: "afa5de02-344d-11e9-a414-719c6709cf3e",
      genres: ['refactoring', 'design']
    },
    {
      title: 'Crime and punishment',
      published: 1866,
      author: 'Fyodor Dostoevsky',
      id: "afa5de03-344d-11e9-a414-719c6709cf3e",
      genres: ['classic', 'crime']
    },
    {
      title: 'The Demon',
      published: 1872,
      author: 'Fyodor Dostoevsky',
      id: "afa5de04-344d-11e9-a414-719c6709cf3e",
      genres: ['classic', 'revolution']
    },
  ]
  