is x: (with colon) a valid inst var name ?

I can create the following object

Object subclass: #InstVarNameTest
�� instanceVariableNames: 'x:'
�� classVariableNames: ''
�� category: 'TTT'

But of course, I can not write an assignment statement.

I am asking because if

Symbol>>#asMutator is called an a symbol with colon like x:

it returns

x::

It looks like that x:: is not even a valid message selector.

I would like to change the asMutator method to return

x: if it is called on x:

(or throw an error ?)

nicolai