Use default hash method to return hash value of a piece of Python
        picklable object.

        :param pyobj: any python object

def of_pyobj(self, pyobj):
        """
        Use default hash method to return hash value of a piece of Python
        picklable object.

        :param pyobj: any python object
        """
        m = self.hash_algo()
        m.update(pickle.dumps(pyobj, protocol=self.pk_protocol))
        return self.digest(m)