anchor.diff:    }
   }
   
  -/// Puts a buffer in front of an [IOSink].
  +/// Puts a buffer in front of a [Sink<List<int>>].
   class BufferedSink {
     static const int SIZE = 100000;
     static const int SMALL = 10000;
  -  final IOSink _sink;
  +  final Sink<List<int>> _sink;
     Uint8List _buffer = new Uint8List(SIZE);
     int length = 0;
   
  
positive.code: import '../ast.dart';
  import '../import_table.dart';
  import 'tag.dart';
  import 'dart:io';
  import 'dart:convert';
  import 'dart:typed_data';
  import 'dart:collection';
  
negative.code:   /// If multiple binaries are to be written based on the same IR, a shared
    /// [globalIndexer] may be passed in to avoid rebuilding the same indices
    /// in every printer.
    BinaryPrinter(Sink<List<int>> sink, {GlobalIndexer globalIndexer})
        : _sink = new BufferedSink(sink),
          _globalIndexer = globalIndexer ?? new GlobalIndexer();
  
  