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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 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