Page linking doesn't work and linking custom models doesn't work according to the documentation

The following code:
```python
    def real_value(self):
        return self.model.objects.filter(pk=self.link.data('value')).first()
```
When attached to djangocms_blog.Post model `self.link.data('value')` returns `{'model': 7}`, which of course can't be used as a filter for PK, ie `self.model.objects.filter(pk={'model': 7})` returns an error.