Unblocks messages from a blocked user

        :param user_id: The ID of the user that you want to unblock
        :return: Whether the request was successful
        :raises: FBchatException if request failed

def unblockUser(self, user_id):
        """
        Unblocks messages from a blocked user

        :param user_id: The ID of the user that you want to unblock
        :return: Whether the request was successful
        :raises: FBchatException if request failed
        """
        data = {"fbid": user_id}
        r = self._post(self.req_url.UNBLOCK_USER, data)
        return r.ok