anchor.diff:          (elements['constant'] as Map).values.map((c) => parseConstant(c)));
   
       input['holding'].forEach((k, deps) {
  -      CodeInfo src = registry[k];
  -      assert(src != null);
  +      final src = registry[k] as CodeInfo;
         for (var dep in deps) {
  -        var target = registry[dep['id']];
  -        assert(target != null);
  +        final target = registry[dep['id']]!;
           src.uses.add(DependencyInfo(target, dep['mask']));
         }
       });
   
       input['dependencies']?.forEach((String k, dependencies) {
         List<String> deps = dependencies;
  -      result.dependencies[registry[k]] = deps.map((d) => registry[d]).toList();
  +      result.dependencies[registry[k]!] =
  +          deps.map((d) => registry[d]!).toList();
       });
   
       result.outputUnits
  
positive.code:       } else if (serializedId.startsWith('outputUnit/')) {
          return OutputUnitInfo.internal();
        }
        assert(false);
        return null;
      });
    }
  
  
negative.code:   }
  
    FunctionInfo parseFunction(Map json) {
      final result = parseId(json['id']) as FunctionInfo;
      return result
        ..name = json['name']
        ..parent = parseId(json['parent'])
        ..coverageId = json['coverageId']
        ..outputUnit = parseId(json['outputUnit']) as OutputUnitInfo?
        ..size = json['size']
        ..functionKind = json['functionKind']
        ..type = json['type']
  