anchor.diff:                "type, '${parameterTypeElement.name}', and cannot be stubbed.");
           }
         } else if (parameterType is analyzer.FunctionType) {
  -        errorMessages
  -            .addAll(_checkFunction(parameterType, name, className, entryLib));
  +        errorMessages.addAll(_checkFunction(parameterType, name, className));
         }
       }
   
  
positive.code:                 'type, and cannot be stubbed.');
        }
      } else if (returnType is analyzer.FunctionType) {
        errorMessages
            .addAll(_checkFunction(returnType, name, className, entryLib));
      } else if (returnType is analyzer.TypeParameterType) {
        if (function.returnType is analyzer.TypeParameterType &&
            entryLib.typeSystem.isPotentiallyNonNullable(function.returnType)) {
          errorMessages
              .add("The method '$className.$name' features a non-nullable "
                  'unknown return type, and cannot be stubbed.');
  
negative.code:   /// This function is responsible for ensuring that each value is an
    /// appropriate target for mocking. It will throw an
    /// [InvalidMockitoAnnotationException] under various conditions.
    static List<analyzer.DartType> _mapAnnotationValuesToClasses(
        Iterable<DartObject> objectsToMock, TypeProvider typeProvider) {
      var classesToMock = <analyzer.DartType>[];
  
  