anchor.diff:      }, 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) {
  
positive.code: 
    /// 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);
      });
  
      return Process.start(executable, flags).then((Process process) {
        StringBuffer errors = new StringBuffer();
  
negative.code: import 'dart:async';
  import 'dart:io';
  import 'package:utf/utf.dart';
  
  /// Facade for Sass-transformations.
  class Sass {
  