Question: recommended way not make proc return back result of last statement?

Given a module A, it has a proc which is called to set some internal variable to some value. This proc is meant to be used as initialization of the module, and not meant to return anything (i.e. procedure vs. a function in other languages, where a procedure does not return anything, but a function does).

When this proc is called from outside, the result of the last assignment in the proc is returned back to the user since that is the default behavior.

Is there a way to prevent this, other than adding an explicit NULL at the end of this proc?  Adding : at the end the last statement or at the end of the proc did not prevent this.

Here is an example

restart;
A:=module()
  local r::integer;
  export set_r:=proc(r::integer)   
    A:-r:= r:   
  end proc:
end module:

Now when calling  A:-set_r(10), Maple will return back/echo back 10. But this is not something I want.

A:-set_r(10);

    10

To prevent this, currently I add NULL; at end of the proc, like this

A:=module()
  local r::integer;
  export set_r:=proc(r::integer)   
    A:-r:= r:   
    NULL;
  end proc:
end module:

and now

A:-set_r(10);

returns nothing. Well, it returns NULL but that is like nothing.

My question is, is there a better way to do this? Can one define a proc in Maple that returns nothing?

Maple 2022.1