Used to get a raw attribute from Sovrin
        :param attrib: attribute to add
        :return: number of pending txns

def requestAttribute(self, attrib: Attribute, sender):
        """
        Used to get a raw attribute from Sovrin
        :param attrib: attribute to add
        :return: number of pending txns
        """
        self._attributes[attrib.key()] = attrib
        req = attrib.getRequest(sender)
        if req:
            return self.prepReq(req, key=attrib.key())