'Given captured args and kwargs from the URLconf, saves something in
self.state and/or raises Http404 if necessary.
For example, this URLconf captures a user_id variable:
(r\'^contact/(?P<user_id>\d{1,6})/$\', MyFormPreview(MyForm)),
In this case, the kwargs variable in parse_params would be
{\'user_id\': 32} for a request to \'/contact/32/\'. You can use that
user_id to make sure it\'s a valid user and/or save it for later, for
use in done().'

def parse_params(self, *args, **kwargs):

    pass
