What version of Delphi introduced helpers?

Question

Delphi

Actually a question.

type
    TMyClassHelper = class helper for TMyClass
      procedure HelloWorld;
      function MyFunc: Integer;
    end;
 
    ...
 
    procedure TMyClassHelper.HelloWorld;
    begin
       Writeln(Self.ClassName); // Self refers to TMyClass type, not TMyClassHelper
    end;
 
    function TMyClassHelper.MyFunc: Integer;
    begin
      ...
    end;

In what version of Delphi did all this appear? Is it in XE2 or not?

Answer 1

I answer myself again. XE3.