huh ?
I did not add this method, it was stamped al 9/16/2005

2009/12/25  <commits at source.squeak.org>:
> Nicolas Cellier uploaded a new version of Kernel to project The Trunk:
> http://source.squeak.org/trunk/Kernel-nice.344.mcz
>
> ==================== Summary ====================
>
> Name: Kernel-nice.344
> Author: nice
> Time: 25 December 2009, 7:23:49 am
> UUID: 5e5f0f23-ff9c-4f2c-b175-21cc8a639d6d
> Ancestors: Kernel-nice.343
>
> fix #formalParametersAt: with new support method in Parser
>
> Note: this method has no senders in trunk.
> I suspect it does not have much value...
> I presume it could have been used by refactoring tools, but RB must be using its own parser...
> Anyone knows of a package using #formalParametersAt: ?
>
> =============== Diff against Kernel-nice.343 ===============
>
> Item was added:
> + ----- Method: Behavior>>formalParametersAt: (in category 'accessing method dictionary') -----
> + formalParametersAt: aSelector
> +       "Return the names of the arguments used in this method."
> +
> +       | source |
> +       source := self sourceCodeAt: aSelector ifAbsent: [^ #()].       "for now"
> +       ^(self parserClass new) parseParameterNames: source!
>
>
>