anchor.diff:  
   /// Load an import resource and return a [Future] with a [List] of its lines.
   /// Returns [null] instead of a list if the resource could not be loaded.
  -Future<List> loadResource(String import) {
  -  if (import.startsWith("http")) {
  +Future<List> loadResource(String uri) {
  +  if (uri.startsWith("http")) {
       Completer c = new Completer();
       HttpClient client = new HttpClient();
  -    client.getUrl(Uri.parse(import))
  +    client.getUrl(Uri.parse(uri))
           .then((HttpClientRequest request) {
             return request.close();
           })
  
positive.code: 
    /// Returns the absolute path wrt. to the given environment or null, if the
    /// import could not be resolved.
    resolve(String import) {
      if (import.startsWith(DART_PREFIX)) {
        if (_env["sdkRoot"] == null) {
          // No sdk-root given, do not resolve dart: URIs.
          return null;
        }
        var slashPos = import.indexOf("/");
        var filePath;
        if (slashPos != -1) {
          var path = import.substring(DART_PREFIX.length, slashPos);
          // Drop patch files, since we don't have their source in the compiled
          // SDK.
          if (path.endsWith("-patch")) {
            failed.add(import);
            return null;
          }
          // Canonicalize path. For instance: _collection-dev => _collection_dev.
          path = path.replaceAll("-", "_");
          filePath = "${_env["sdkRoot"]}"
                     "/${path}${import.substring(slashPos, import.length)}";
        } else {
          // Resolve 'dart:something' to be something/something.dart in the SDK.
          var lib = import.substring(DART_PREFIX.length, import.length);
          filePath = "${_env["sdkRoot"]}/${lib}/${lib}.dart";
        }
        return filePath;
      }
      if (import.startsWith(PACKAGE_PREFIX)) {
        if (_env["pkgRoot"] == null) {
          // No package-root given, do not resolve package: URIs.
          return null;
        }
        var filePath =
            "${_env["pkgRoot"]}"
            "/${import.substring(PACKAGE_PREFIX.length, import.length)}";
        return filePath;
      }
      if (import.startsWith(FILE_PREFIX)) {
        var filePath = fromUri(Uri.parse(import));
        return filePath;
      }
      if (import.startsWith(HTTP_PREFIX)) {
        return import;
      }
      // We cannot deal with anything else.
      failed.add(import);
      return null;
    }
  }
  
negative.code:         });
      return c.future;
    } else {
      File f = new File(uri);
      return f.readAsLines()
          .catchError((e) {
            return new Future.value(null);
  