anchor.diff:  
       // A<num>
       // A<T>
  -    var aNum = interfaceType(A,
  -        typeArguments: [numNone], nullabilitySuffix: NullabilitySuffix.none);
  -    var aT = interfaceType(A,
  -        typeArguments: [tType], nullabilitySuffix: NullabilitySuffix.none);
  +    var aNum = interfaceTypeNone(A, typeArguments: [numNone]);
  +    var aT = interfaceTypeNone(A, typeArguments: [tType]);
   
       _checkIsSubtypeMatchOf(aT, aNum, [tType], ['out T <: num'],
           covariant: true);
  
positive.code: 
  import 'package:analyzer/dart/ast/standard_ast_factory.dart';
  import 'package:analyzer/dart/ast/token.dart';
  import 'package:analyzer/dart/element/nullability_suffix.dart';
  import 'package:analyzer/dart/element/type.dart';
  import 'package:analyzer/error/listener.dart';
  import 'package:analyzer/src/dart/ast/token.dart';
  
negative.code: 
      // A<num>
      // A<T>
      var aNum = interfaceTypeNone(A, typeArguments: [numNone]);
      var aT = interfaceTypeNone(A, typeArguments: [tType]);
  
      _checkIsSubtypeMatchOf(
          aT, aNum, [tType], ['inout T <: num', 'num <: inout T'],
  