anchor.diff:  import '../ast.dart';
   import '../import_table.dart';
   import 'tag.dart';
  -import 'dart:io';
   import 'dart:convert';
   import 'dart:typed_data';
   import 'dart:collection';
  
positive.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(IOSink sink, {GlobalIndexer globalIndexer})
        : _sink = new BufferedSink(sink),
          _globalIndexer = globalIndexer ?? new GlobalIndexer();
  
  
negative.code:   }
  }
  
  /// Puts a buffer in front of a [Sink<List<int>>].
  class BufferedSink {
    static const int SIZE = 100000;
    static const int SMALL = 10000;
    final Sink<List<int>> _sink;
    Uint8List _buffer = new Uint8List(SIZE);
    int length = 0;
  
  