anchor.diff:  import 'dart:io';
   
   import 'package:barback/barback.dart';
  -import 'package:path/path.dart' as path;
  +import 'package:path/path.dart' as p;
   import 'package:stack_trace/stack_trace.dart';
   import 'package:watcher/watcher.dart';
   
  
positive.code:           if (event.path.endsWith(".dart.precompiled.js")) return;
  
            var id = new AssetId(package.name,
                path.relative(event.path, from: package.dir));
            if (event.type == ChangeType.REMOVE) {
              barback.removeSources([id]);
            } else {
  
negative.code: 
        // Watch the visible package directories for changes.
        return Future.wait(getPublicDirectories(package.name).map((name) {
          var subdirectory = p.join(package.dir, name);
          if (!dirExists(subdirectory)) return new Future.value();
  
          // TODO(nweiz): close these watchers when [barback] is closed.
  