src/Shelf.java:2: error: cannot find symbol
  int count() { return books.size(); }
                       ^
  symbol:   variable books
  location: class Shelf
src/Shelf.java:3: error: cannot find symbol
  String title() { return booksTitle; }
                          ^
  symbol:   variable booksTitle
  location: class Shelf
src/Shelf.java:4: error: cannot find symbol
  int more() { return books.length; }
                      ^
  symbol:   variable books
  location: class Shelf
3 errors
