public LinkedList<Diff> diff_main(String text1, String text2,
      boolean checklines) {
    // Set a deadline by which time the diff must be complete.
    long deadline;
    if (Diff_Timeout <= 0) {
      deadline = Long.MAX_VALUE;
    } else {
      deadline = System.currentTimeMillis() + (long) (Diff_Timeout * 1000);
    }
    return diff_main(text1, text2, checklines, deadline);
  }
Find the differences between two texts.

@param text1 Old string to be diffed.
@param text2 New string to be diffed.
@param checklines Speedup flag.  If false, then don't run a line-level diff first to identify
the changed areas. If true, then run a faster slightly less optimal diff.
@return Linked List of Diff objects.
src/burp/Utils/diff_match_patch.java