anchor.diff:  
       function AddElement(Name: TmXMLString): TmXmlElement;
       function HasAttribute(const Name: TmXMLString): boolean;
  +    procedure DeleteAttribute(const aName : TmXMLString);
       procedure SetAttribute(aName, aValue: TmXmlString); overload;
       procedure SetAttribute(aName: TmXmlString; const aValue: TNullableString); overload;
       function GetAttribute(const aName: TmXmlString): TmXmlString; overload;
  
positive.code: procedure TmXmlElement.SetAttribute(aName: TmXmlString; const aValue: TNullableString);
  begin
    if aValue.NotNull then
      Self.SetAttribute(aName, aValue.Value);
  end;
  
  procedure TmXmlElement.SetDateTimeAttribute(const aName: TmXmlString; const aValue: TDateTime);
  
negative.code:   FImpl._SetValue(aValue);
  end;
  
  procedure TmXmlElement.SetValue(const aValue: TNullableString);
  begin
    if aValue.NotNull then
      FImpl._SetValue(aValue.AsString);
  end;
  
  function TmXmlElement.GetValue: TmXMLString;
  begin
    Result := FImpl._GetValue;
  