def _check_response(self, rpc_obj, snippet_name, conf_str=None):
        """This function checks the rpc response object for status.

        This function takes as input the response rpc_obj and the snippet name
        that was executed. It parses it to see, if the last edit operation was
        a success or not.
            <?xml version="1.0" encoding="UTF-8"?>
            <rpc-reply message-id="urn:uuid:81bf8082-....-b69a-000c29e1b85c"
                       xmlns="urn:ietf:params:netconf:base:1.0">
                <ok />
            </rpc-reply>
        In case of error, IOS XE device sends a response as follows.
        We take the error type and tag.
            <?xml version="1.0" encoding="UTF-8"?>
            <rpc-reply message-id="urn:uuid:81bf8082-....-b69a-000c29e1b85c"
            xmlns="urn:ietf:params:netconf:base:1.0">
                <rpc-error>
                    <error-type>protocol</error-type>
                    <error-tag>operation-failed</error-tag>
                    <error-severity>error</error-severity>
                </rpc-error>
            </rpc-reply>
        :return: True if the config operation completed successfully
        :raises: networking_cisco.plugins.cisco.cfg_agent.cfg_exceptions.
        IOSXEConfigException
        """
        LOG.debug("RPCReply for %(snippet_name)s is %(rpc_obj)s",
                  {'snippet_name': snippet_name, 'rpc_obj': rpc_obj.xml})
        xml_str = rpc_obj.xml
        if "<ok />" in xml_str:
            # LOG.debug("RPCReply for %s is OK", snippet_name)
            LOG.info("%s was successfully executed", snippet_name)
            return True
        # Not Ok, we throw a ConfigurationException
        e_type = rpc_obj._root[0][0].text
        e_tag = rpc_obj._root[0][1].text
        params = {'snippet': snippet_name, 'type': e_type, 'tag': e_tag,
                  'dev_id': self.hosting_device['id'],
                  'ip': self._host_ip, 'confstr': conf_str}
        raise cfg_exc.IOSXEConfigException(**params)