Sample code in the documentation of unit TypInfo hardly usable

I never can remember the syntax for the function GetEnumName which allows to convert an enumeration to a string representation. Today I tried the sample code shown in the official documentation: https://www.freepascal.org/docs-html/current/rtl/typinfo/getenumname.html

program example9;

{ This program demonstrates the GetEnumName, GetEnumValue functions }

{$mode objfpc}

uses rttiobj,typinfo;

Var
  O : TMyTestObject;
  TI : PTypeInfo;

begin
  O:=TMyTestObject.Create;
  TI:=GetPropInfo(O,'MyEnumField')^.PropType;
  Writeln('GetEnumName           : ',GetEnumName(TI,Ord(O.MyEnumField)));
  Writeln('GetEnumValue(mefirst) : ',GetEnumName(TI,GetEnumValue(TI,'mefirst')));
  O.Free;
end.

I copied this code into Lazarus and tried to compile: Unit rttiobj not found...

After some searching I saw a note in the root page of the typinfo documentation saying that "the examples in this chapter use a rttiobj auxiliary unit, which contains an object that has a published property for all supported types. It also contains some auxiliary routines and definitions. This unit is included in the documentation sources, in the directory typinfex."

Seriously? I need to search for a unit in the documentation sources to run this simple documentation code? I don't even know where the documentation sources are...

There are lots of enumerations in the rtl and fcl. Why not use one of them in the example? Here is a modified version of the sample code which the user can apply immediately:

program example9;

{ This program demonstrates the GetEnumName, GetEnumValue functions }

{$mode objfpc}

uses
  Classes, typinfo;

var
  al: TAlignment;    // TAlignment is declared in classes as (taLeftJustify, taRightJustify, taCenter)

begin
  al := taLeftJustify;
  WriteLn(GetEnumName(TypeInfo(TAlignment), ord(al)));
  WriteLn(GetEnumValue(TypeInfo(TAlignment), 'taLeftJustify'));
end. 

Note: all the documentation pages of the typinfo unit suffer from this issue.