 
     // MARK: - Navigation
 
-    // In a storyboard-based application, you will often want to do a little preparation before navigation
     override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
 
         guard let identifier = segue.identifier else { return }


        let lastHa1cReading = trendsAlgorithmModel.ha1cArray.last as? Ha1cReading
        ha1cValueLabel.text = TrendsViewController.ha1cText(reading: lastHa1cReading)

        let ha1cTapGesture = UITapGestureRecognizer(target: self,
                                                    action: #selector(ha1cViewTapped(_:)))
        ha1cView.addGestureRecognizer(ha1cTapGesture)

        let bloodGlucoseTapGesture = UITapGestureRecognizer(target: self,
                                                    action: #selector(bloodGlucoseViewTapped(_:)))
        bloodGlucoseView.addGestureRecognizer(bloodGlucoseTapGesture)

    }



    class func bloodGlucoseText(reading: BGReading?) -> String {
        if reading == nil {

    override func viewDidLoad() {
        super.viewDidLoad()

        title = "Trends"

        configureReadings()
        configureBloodGlucoseViewGesture()
        configureHa1cViewGesture()
    }

    func configureReadings() {
        // reference TrendsContainerViewController
        let trendsAlgorithmModel = TrendsAlgorithmModel.sharedInstance() as! TrendsAlgorithmModel

