anchor.diff:  
   /// Analyzes set of libraries and provides a mirror system which can be used
   /// for static inspection of the source code.
  -Future<MirrorSystem> _analyzeLibraries(List<Uri> libraries,
  +Future<MirrorSystem> _analyzeLibraries(List<String> libraries,
         String libraryRoot, {String packageRoot}) {
     SourceFileProvider provider = new CompilerSourceFileProvider();
     api.DiagnosticHandler diagnosticHandler =
  
positive.code: 
  /// Analyzes set of libraries by getting a mirror system and triggers the
  /// documentation of the libraries.
  Future<MirrorSystem> getMirrorSystem(List<Uri> libraries,
      {String packageRoot, bool parseSdk: false}) {
    if (libraries.isEmpty) throw new StateError('No Libraries.');
    // Finds the root of SDK library based off the location of docgen.
  
negative.code:   return libraries;
  }
  
  List<String> _listDartFromDir(String args) {
    var libraries = [];
    // To avoid anaylzing package files twice, only files with paths not
    // containing '/packages' will be added. The only exception is if the file to
  