Watchface: Volumes

In v1.14 I added pulse ox as a data option. My goal was grab whatever value was shown in the pulse ox widget and display it on the watch face. This proved to be pretty challenging. I found that the pulse ox iterator didn't always return values I expected. I often ended up with a null reading when the last pulse ox sample was more than ~30 minutes old. Here's the implementation I went with. It's not perfect, but it matches the reading in the pulse ox widget most of the time. 

// Initialize variable to hold the iterator for pulse ox samples
var pulseOxIterator = null;

// Check if device supports SensorHistory and oxygen saturation history
if ((Toybox has :SensorHistory) && (Toybox.SensorHistory has :getOxygenSaturationHistory)) {
    // Get the latest oxygen saturation sample (only 1 sample to avoid issues with multiple)
    pulseOxIterator = Toybox.SensorHistory.getOxygenSaturationHistory({
        :period => 1, 
        :order => SensorHistory.ORDER_NEWEST_FIRST
    });
}

// Validate the iterator and the sample data before storing the pulse ox value
if ((pulseOxIterator != null) && (pulseOxIterator.next() != null) && (pulseOxIterator.next().data != null)) {
    // Store the valid pulse ox sample in persistent storage
    Storage.setValue("pulseOxDataKey", pulseOxIterator.next().data);
}

// Retrieve the last valid pulse ox sample from storage
var lastValidPulseOx = Storage.getValue("pulseOxDataKey");

Let me know if you have a cleaner/nicer/simpler way achieving this. Thanks!