anchor.diff:    FIsNull := false;
   end;
   
  -class function TNullableBoolean.CreateNew(aValue: Boolean): TNullableBoolean;
  -var
  -  tmp : TNullableBoolean;
  -begin
  -  tmp := TNullableBoolean.Create();
  -  tmp.Value := aValue;
  -  Result := tmp;
  -end;
  -
  -class function TNullableBoolean.CreateNew: TNullableBoolean;
  -begin
  -  Result := TNullableBoolean.Create();
  +constructor TNullableBoolean.Create;
  +begin
  +  inherited Create;
  +end;
  +
  +constructor TNullableBoolean.Create(aValue: Boolean);
  +begin
  +  inherited Create;
  +  FValue := aValue;
   end;
   
   procedure TNullableBoolean.Assign(aSource: TNullableBoolean);
  
positive.code:   FIsNull := false;
  end;
  
  class function TNullableDateTime.CreateNew(aValue: TDateTime): TNullableDateTime;
  var
    tmp : TNullableDateTime;
  begin
    tmp := TNullableDateTime.Create();
    tmp.Value := aValue;
    Result := tmp;
  end;
  
  class function TNullableDateTime.CreateNew: TNullableDateTime;
  begin
    Result := TNullableDateTime.Create();
  end;
  
  procedure TNullableDateTime.Assign(aSource: TNullableDateTime);
  
negative.code:     function GetValue : Integer;
      procedure SetValue(AValue: Integer);
    public
      constructor Create(); override; overload;
      constructor Create(aValue: Integer); overload;
  
      procedure Assign(aSource : TNullableInteger); overload;
      procedure Assign(aSourceField : TField); override; overload;
  