I'm trying to create a service in Polymer but I don't understand how I'm supposed to create static properties.

I would need them to share the same value for all instances ("static") BUT I would also need the observers to be triggered on every instance when they are updated.

I know I could create a variable in the scope of the Polymer() call like this :

```
var users = [];
Polymer({
  is: 'my-service',
  properties: {
    users: {
      type: Array,
      value: users,
      notify: true,
    }
  },
  // ...
});

```

But it doesn't meet the second criteria. If I update it from one instance, it doesn't trigger the observers of the other instances.

Do you know how to perform that without triggering the observers on each instance manually ? (I could do it but it would defeat the idea of using a framework in this case.)

EDIT: An alternative would be to create a singleton, but I don't think it's possible.