anchor.diff:    return fixedPath;
   }
   
  +
   _enforceTrailingSlash(uri) {
     // Ensure we have a trailing slash character.
     if (!uri.endsWith('/')) {
  
positive.code:     throw "URIs using the 'file:' scheme may not contain a host.";
    }
  
    _logResolution('# Path: $uri -> ${uri.path}');
    return uri.path;
  }
  
  
  
negative.code: }
  
  
  _extractDriveLetterPrefix(cwd) {
    if (!_isWindows) {
      return null;
    }
    if (cwd.length > 1 && cwd[1] == ':') {
      return '/${cwd[0]}:';
    }
    return null;
  }
  
  
  void _setWorkingDirectory(cwd) {
    _workingWindowsDrivePrefix = _extractDriveLetterPrefix(cwd);
    cwd = _sanitizeWindowsPath(cwd);
    cwd = _enforceTrailingSlash(cwd);
    _workingDirectoryUri = new Uri(scheme: 'file', path: cwd);
  