def call_eval(self, value, caller, return_value=True, **kwargs):
        """
            Value might be either name registered in System namespace, or object, either
            StatusObject or Callable. If Callable, evaluate :meth:`.call` method. If StatusObject,
            return status.
        """
        value = self.name_to_system_object(value)
        if return_value and isinstance(value, AbstractStatusObject):
            return value.status
        if hasattr(value, 'call'):
            return self.call_eval(value.call(caller, **kwargs), caller, return_value, **kwargs)
        else:
            return value
Value might be either name registered in System namespace, or object, either
            StatusObject or Callable. If Callable, evaluate :meth:`.call` method. If StatusObject,
            return status.