var data = JSON.parse(value),
	lookup = {},
	result = [];
for (var item, i = 0; item = data[i++];) {
	var code = item.labels.grpc_code;
	if (!(code in lookup)) {
		lookup[code] = 1;
		result.push({ "{#GRPC.CODE}": code });
	}
}
return JSON.stringify(result);