Example::

            /browse/homes/ca/ -> ca
            /browse/homes/ca/los-angeles-county/ -> los-angeles-county
            /browse/homes/ca/los-angeles-county/91001/ -> 91001
            /browse/homes/ca/los-angeles-county/91001/tola-ave_5038895/ -> tola-ave_5038895

        :return:

def key(self):
        """
        Example::

            /browse/homes/ca/ -> ca
            /browse/homes/ca/los-angeles-county/ -> los-angeles-county
            /browse/homes/ca/los-angeles-county/91001/ -> 91001
            /browse/homes/ca/los-angeles-county/91001/tola-ave_5038895/ -> tola-ave_5038895

        :return:
        """

        return [part.strip() for part in self.href.split("/") if part.strip()][
            -1]