anchor.diff:      if (branchCoverage != null) {
         hits.branchHits ??= <int, int>{};
         forEachLine(branchCoverage.hits!, (line) {
  -        _incrementCountForKey(hits.branchHits!, line);
  +        hits.branchHits!.increment(line);
         });
         forEachLine(branchCoverage.misses!, (line) {
           hits.branchHits!.putIfAbsent(line, () => 0);
  
positive.code: 
  import 'package:vm_service/vm_service.dart';
  
  import 'util.dart';
  import 'hitmap.dart';
  
  const _retryInterval = Duration(milliseconds: 200);
  const _debugTokenPositions = bool.fromEnvironment('DEBUG_COVERAGE');
  
negative.code:   return coverage;
  }
  
  extension _MapExtension<T> on Map<T, int> {
    void increment(T key) => this[key] = (this[key] ?? 0) + 1;
  }
  
  Future<String> _getFuncName(
  