def remove(self, what, call):
type = observerTypeEnum.typeOf(what)<EOL>self._observers.remove({<EOL>"<STR_LIT>": what,<EOL>"<STR_LIT:type>": type,<EOL>"<STR_LIT>": call<EOL>})<EOL>
remove an observer

what: (string | array) state fields to observe
call: (function) when not given, decorator usage is assumed.
    The call function should have 2 parameters:
    - previousValue,
    - actualValue