var lookup = {},
    result = [];

JSON.parse(value).forEach(function (item) {
        var envoy_listener_address = item.labels.envoy_listener_address;

        if (lookup[envoy_listener_address]) {
            return;
        }
        lookup[envoy_listener_address] = 1;
        result.push({
            '{#LISTENER_ADDRESS}': envoy_listener_address
        });
});

return JSON.stringify(result);