anchor.diff:  import 'dart:async' show Future, StreamController;
   import 'dart:convert' show JsonEncoder;
   import 'dart:io' show Directory, File;
  -import 'dart:typed_data' show Uint8List;
   
   import 'package:collection/collection.dart' show compareNatural;
   import 'package:path/path.dart' as path;
  
positive.code:     String content = template(data,
          assumeNullNonExistingProperty: false, errorOnMissingProperty: true);
  
      // If you see this assert, we're probably being called to build non-canonical
      // docs somehow.  Check data.self.isCanonical and callers for bugs.
      assert(!writtenFiles.contains(fullName));
      _writeFile(fullName, content);
      writtenFiles.add(fullName);
      if (data.self is ModelElement) documentedElements.add(data.self);
    }
  
    void _writeFile(String filename, String content) {
      File file = _createOutputFile(filename);
      file.writeAsStringSync(content);
      _onFileCreated.add(file);
    }
  }
  
  File _createOutputFile(String filename) {
    File file = new File(filename);
    Directory parent = file.parent;
    if (!parent.existsSync()) parent.createSync(recursive: true);
    return file;
  }
  
negative.code:             'encountered $resourcePath');
        }
        String destFileName = resourcePath.substring(prefix.length);
        _writeFile(path.join(out.path, 'static-assets', destFileName),
            await loader.loadAsBytes(resourcePath));
      }
    }
  
  