First of all the mentioned code is two lines below this commented line.
Second, we need to ensure an positive long value, should we instead use something like:
```python
    try:
        self._max_age = abs(long(self._config.get("adhocracy.session_lifetime")
    except:
        pass
```
to ensure the variable self._max_age is None and defined, in a way that test like
```python
   if self._max_age is not None:
```
do not fail with an `NameError: name 'self._max_age' is not defined`

So that we can check in the `_cookie_options` if we have to set the `Max-Age` for the cookie, or avoid if its not set.