anchor.diff:  
           String ext = extension(file.path);
           if (_extToContentType.containsKey(ext.toLowerCase())) {
  -          response.headers.contentType =
  -              ContentType.parse(_extToContentType[ext.toLowerCase()]);
  +          response.headers.contentType = ContentType.parse(_extToContentType[ext.toLowerCase()]);
           }
   
           if (request.method == 'HEAD') {
  
positive.code:       _errorHandler(e);
      }
  
      file.lastModified().then((lastModified) {
        // If If-Modified-Since is present and file haven't changed, return 304.
        if (request.headers.ifModifiedSince != null &&
  
negative.code:         // If the Range header was received, handle it.
          String range = request.headers.value("range");
          if (range != null) {
            _sendRange(file, response, range, length);
            return;
          }
  
          /*
  