anchor.diff:      implements ExecutableElement, ElementImplWithFunctionType {
     /// A list containing all of the parameters defined by this executable
     /// element.
  -  List<ParameterElement> _parameters = _Sentinel.parameterElement;
  +  List<ParameterElement> _parameters = const [];
   
     /// The inferred return type of this executable element.
     DartType? _returnType;
  
positive.code: 
    @override
    String? get defaultValueCode {
      final linkedNode = this.linkedNode;
      if (linkedNode is DefaultFormalParameter) {
        return linkedNode.defaultValue?.toSource();
      }
  
      return _defaultValueCode;
    }
  
  
negative.code:   /// A list containing all of the parameters defined by this parameter element.
    /// There will only be parameters if this parameter is a function typed
    /// parameter.
    List<ParameterElement> _parameters = const [];
  
    /// A list containing all of the type parameters defined for this parameter
    /// element. There will only be parameters if this parameter is a function
    /// typed parameter.
    List<TypeParameterElement> _typeParameters = const [];
  
    /// The kind of this parameter.
    ParameterKind? _parameterKind;
  