Where to write methods for test registration?

In all examples, the test registration methods are written in the class

      type
       TCalc=class
        private
         class Procedure _RegisterMethod; // Register TestMethods
         class  Function _TestMethods( IMethod:IRunMethodParam    // Test Methods
                            ):TTestResultParam;// Result Test
         ...

Registration methods can be prescribed anywhere, in any class and even without a class.

For example we can write registration methods in another class TCalcTest:

Class TCalcTest can be in the source module and external.

 type
TCalcTest=class
private class Procedure _RegisterMethod; // Register TestMethods
class Function _TestMethods( IMethod:IRunMethodParam // Test Methods
 ):TTestResultParam;// Result Test
...

ou can make a class collection for tests of various many classes

      type
       TTestCollections=class
        private
        // TCalc
         class Procedure TCalc_RegisterMethod; // Register TestMethods
         class  Function    TCalc_TestMethods( IMethod:IRunMethodParam ):TTestResultParam;
        // TFiles
         class Procedure TFiles_RegisterMethod; // Register TestMethods
         class  Function    TFiles_TestMethods( IMethod:IRunMethodParam ):TTestResultParam;
        // TBitmap
         class Procedure TBitmap_RegisterMethod; // Register TestMethods
         class  Function    TBitmap_TestMethods( IMethod:IRunMethodParam ):TTestResultParam;

You can create test methods outside of classes by slightly changing their description

Procedure NoClass_RegisterMethod(Owner:TObject); // Register TestMethods
Function  NoClass_TestMethods(Owner:TObject;IMethod:IRunMethodParam):TTestResultParam;

and add the code at registration

 var
  rm:TTestRegisterMethod;
  tm:TTestMethodsRun;
begin
 ...
    TMethod(rm).Code:=@NoClass_RegisterMethod;
    TMethod(tm).Code:=@NoClass_TestMethods;
    L_pIndex_NoClass   := IRegisterClass(rm,tm,'TCalc_NoClassTest','No Test classed');