anchor.diff:  
     /// Transforms given Sass-source to CSS.
     Future<String> transform(String content) {
  -    var flags = [];
  -
  -    flags.add('--no-cache');
  -
  -    if (scss)
  -      flags.add('--scss');
  -
  -    if (lineNumbers)
  -      flags.add('--line-numbers');
  -
  -    if (compass)
  -      flags.add('--compass');
  -
  -    if (style != null)
  -      flags..add('--style')..add(style);
  -
  -    loadPath.forEach((dir) {
  -      flags..add('--load-path')..add(dir);
  -    });
  +    var flags = _createFlags();
   
       return Process.start(executable, flags).then((Process process) {
         StringBuffer errors = new StringBuffer();
  
positive.code: import 'dart:async';
  import 'dart:io';
  import 'package:utf/utf.dart';
  import 'package:path/path.dart';
  
  /// Facade for Sass-transformations.
  class Sass {
  
negative.code:     }, test: (e) => e is ProcessException);
    }
  
    List<String> _createFlags() {
      var flags = [];
  
      flags.add('--no-cache');
  
      if (scss)
        flags.add('--scss');
  
      if (lineNumbers)
        flags.add('--line-numbers');
  
      if (compass)
        flags.add('--compass');
  
      if (style != null)
        flags..add('--style')..add(style);
  
      loadPath.forEach((dir) {
        flags..add('--load-path')..add(dir);
      });
  
      return flags;
    }
  
    /// Returns the imports defined in given source.
    static List<String> resolveImportsFromSource(String source) =>
      _importRegex.allMatches(source).map((Match m) {
  