getBooksPossessedByAccount()

 // should return all of the books taken out by an account with the author embedded
  function getBooksPossessedByAccount(account, books, authors) {
    let books_taken = [];
    books.forEach(book=>{
      if (book.borrows.find(item=>item.id === account.id && !item.returned)) {
        books_taken.push(book);
      }
    })
    console.log(books_taken);
    books_taken.forEach(book=>{
      let anAuthor = authors.find(person => person.id === book.authorId);
      book['author'] = anAuthor;
    })
    console.log(books_taken);
    return books_taken;
  }