anchor.diff:    ///     }
     ///
     ///     class AsyncExample extends Vane {
  -  ///       bool async = true;
  +  ///       var async = true;
     ///
     ///       Future main() {
     ///         new Timer(new Duration(seconds: 1), () {
  -  ///           log.info('Running in async!');
  +  ///           log.info('Running asynchronously!');
     ///           next();
     ///         });
     ///
  
positive.code:   ///
    /// Example of middleware that runs asynchronously:
    ///     class TestClass extends Vane {
    ///       void init() {
    ///         pre.add(new AsyncExample());
    ///         pre.add(new AsyncExample());
    ///       }
    ///
    ///       Future main() {
    ///         log.info("Inside TestClass");
    ///         return close();
  
negative.code:   ///
    /// Example of middleware that runs synchronously (default behaviour):
    ///     class TestClass extends Vane {
    ///       var pipeline = [SyncExample, SyncExample, This];
    ///
    ///       @Route("/")
    ///       Future main() {
    ///         log.info('Inside TestClass');
    ///         return close();
  