anchor.diff:        case AnalysisSeverity.none:
           return writtenError.severity;
       }
  -    return null;
     }
   
     String get type => writtenError.type;
  
positive.code:     }
    }
  
    Future<bool> dispose() async {
      await _analyzingController.close();
      await _errorsController.close();
      return _process?.kill();
  
negative.code: // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  import 'dart:async';
  import 'dart:math' as math;
  
  import 'package:process/process.dart';
  
  import '../base/common.dart';
  