How to create static class constants in ES6

ES6 brings classes to JavaScript, but some things are not immediately obvious or entirely supported. For instance, there is no obvious way to create static class constants.

Here is the simplest way I have found to create constants:

class CurrentLocation {
    static get GEOLOCATION_ERROR() { return 'GEOLOCATION_ERROR'; }
    static get GEOLOCATION_REFUSED() { return 'GEOLOCATION_REFUSED'; }
    static get GEOLOCATION_ACQUIRED() { return 'GEOLOCATION_ACQUIRED'; }
    static get GEOLOCATION_PENDING() { return 'GEOLOCATION_PENDING'; }

    // ...

    function isValid(){
        return this.status === CurrentLocationItem.GEOLOCATION_ACQUIRED
    }
}

In the example below, you can use CurrentLocation.GEOLOCATION_ERROR anywhere, but myGeolocationItem.GEOLOCATION_ERROR will not exist, as static members are not visible to class instances. Moreover, children of the CurrentLocation class will not inherit these attributes.