anchor.diff:    String sdkRoot;
     String pkgRoot;
     var input;
  -  var output;
  +  IOSink output;
     int workers;
     bool prettyPrint;
     bool lcov;
  
positive.code:       entry.write("DA:${k},${v[k]}\n");
      });
      entry.write("end_of_record\n");
      env.output.write(entry.toString());
      return new Future.value(null);
    };
  
  
negative.code: ///
  /// Returns a [Future] that completes as soon as all map entries have been
  /// emitted.
  Future lcov(Map hitmap, IOSink output) {
    var emitOne = (key) {
      var v = hitmap[key];
      StringBuffer entry = new StringBuffer();
  