The #= specialization for SObject and String might not hold for some classes that do implement #= in a non-reflexive way.

- not that we would encourage that, but operators in Smalltalk are not required to be reflexive, I think.

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Added missing import

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Assert invoke(.) is never part of compilation

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Perform should work for all objects

Signed-off-by: Stefan Marr <git@stefan-marr.de>