Same as Session.get_messages, but where ``statuses=["draft"]``.

def get_drafts(self, **kwargs):
        """Same as Session.get_messages, but where ``statuses=["draft"]``."""
        default_kwargs = { "order": "updated_at desc" }
        default_kwargs.update(kwargs)
        return self.get_messages(statuses=["draft"], **default_kwargs)