anchor.diff:              namedNoDefaultParameterHeuristic:
                   NamedNoDefaultParameterHeuristic.assumeRequired));
   
  -    assertConstraint([ConstraintVariable.always],
  -        decoratedTypeAnnotation('int').node.nullable);
  +    assertConnection(
  +        NullabilityNode.always, decoratedTypeAnnotation('int').node);
     }
   
     test_functionDeclaration_resets_unconditional_control_flow() async {
  
positive.code: void f({int i = null}) {}
  ''');
  
      assertConstraint([ConstraintVariable.always],
          decoratedTypeAnnotation('int').node.nullable);
    }
  
    test_functionDeclaration_parameter_named_no_default_assume_nullable() async {
  
negative.code: }
  ''');
      var optional_i = possiblyOptionalParameter('int i');
      assertConnection(NullabilityNode.always, optional_i);
    }
  
    test_functionInvocation_parameter_named_missing_required() async {
  