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