code: public LinkedList<Diff> diff_main(String text1, String text2) {
          return diff_main(text1, text2, true);
      }
docs: Find the differences between two texts. Run a faster, slightly less
  optimal diff. This method allows the 'checklines' of diff_main() to be
  optional. Most of the time checklines is wanted, so default to true.
  
  @param text1
  Old string to be diffed.
  @param text2
  New string to be diffed.
  @return Linked List of Diff objects.