How to insert all Alfresco users into a group with javascript

add_all_users_members_group.js

var group = groups.getGroup("todos");
if (group) {
	logger.warn("encontrado");//

	var usuarios = people.getPeople(null, -1);
	logger.warn(usuarios.length);

	for (var i = 0; i < usuarios.length; i++) {
		var usuario = search.findNode(usuarios[i]);
		var userName = usuario.properties["cm:userName"];

		logger.warn(userName);

		group.addAuthority(userName);
	}
}