Now that we are working with time-dynamic data, we can replace this function with the below.  It's not perfect, but it will figure out some decent defaults for when the data is added to the globe.  Once you make the `_setAvailability` change I mention below, you can drag the us_states into Viewer and it should all work.

```
    KmlDataSource.prototype.getClock = function() {
        var availability = this._dynamicObjectCollection.computeAvailability();
        if (availability.equals(Iso8601.MAXIMUM_INTERVAL)) {
            return undefined;
        }
        var clock = new DynamicClock();
        clock.startTime = availability.start;
        clock.stopTime = availability.stop;
        clock.currentTime = availability.start;
        clock.clockRange = ClockRange.LOOP_STOP;
        clock.clockStep = ClockStep.SYSTEM_CLOCK_MULTIPLIER;
        clock.multiplier = Math.min(Math.max(availability.start.getSecondsDifference(availability.stop) / 60, 60), 50000000);
        return clock;
    };
```