Sequelize salvando muitos para muitos

    var clientID = req.user.client_id;
    return Rule.create(req.body)
    .then(function(newRule){
          var ruleToAdd = newRule;
          return Client.findOne({ where: { id: clientID } })
    .then(function(client){
            return client.addRule(ruleToAdd)
            .then(function(ans){
              return ruleToAdd;
            })
    })