anchor.diff:    @override
     jsAst.Literal encodeGroundRecipe(ModularEmitter emitter, TypeRecipe recipe) {
       return _RecipeGenerator(this, emitter, null, recipe).run().recipe;
  -  }
  -
  -  @override
  -  jsAst.Literal encodeRecipeWithVariablesReplaceByAny(
  -      ModularEmitter emitter, DartType dartType) {
  -    return _RecipeGenerator(this, emitter, null, TypeExpressionRecipe(dartType),
  -            hackTypeVariablesToAny: true)
  -        .run()
  -        .recipe;
     }
   
     @override
  
positive.code:   final TypeEnvironmentStructure _environment;
    final TypeRecipe _recipe;
    final bool metadata;
    final bool hackTypeVariablesToAny;
  
    final List<FunctionTypeVariable> functionTypeVariables = [];
    final Set<TypeVariableType> typeVariables = {};
  
negative.code: 
    jsAst.Literal encodeGroundRecipe(ModularEmitter emitter, TypeRecipe recipe);
  
    /// Returns a [jsAst.Literal] representing [supertypeArgument] to be evaluated
    /// against a [FullTypeEnvironmentStructure] representing [declaringType]. Any
    /// [TypeVariableType]s appearing in [supertypeArgument] which are declared by
  