RBAssignment fail on #removeFromTree if in another assignment

[jecisc]

I have a script removing assignments from some method and I found it bugs when the assignment is not in a sequence but in another assignment.

For example test := test2 := nil.

Tested in Pharo 8.

[jecisc]

Maybe it should inline its value instead of failing. In that case produce: test := nil if we try to remove test2.

[pavel-krivanek]

I guess it is better to let it fail in case it does not know what to do instead of doing something unexpected magically. It is not a refactoring but a low level method. The sanity check should be responsibility of the user.