Callback Error. OnResponse & OnFailure, not functional

public static final String TAG = MainActivity.class.getSimpleName();

private CurrentWeather mCurrentWeather;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);  //attaches layout to THIS activity
    ButterKnife.bind(this);

    mProgressBar.setVisibility(View.INVISIBLE); //Will superimpose the progressbar on top of the refresh button. It will show only when we get new data


    //Forecast Latitude and Longitude
    final double latitude = 37.8267;
    final double longitude = -122.4233;



    mRefreshImageView.setOnClickListener(  new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            getForecast(latitude, longitude);
        }
    }  );

    //Below...Check to see that a network connection is available before making a network call
        //If true, run http request
        //If false, notify user via a Toast

    getForecast(latitude, longitude);

    Log.d(TAG, "Main UI Code is Running!");
}

private void getForecast( double latitude,double longitude) {
    String apiKey = "f5d3eda07bc28ebd39b109bd0a11d91b";

    String forecastUrl = "https://api.darksky.net/forecast/" + apiKey+ "/" + latitude + "," + longitude; // Full Sample URL for Alcatraz Weather. We have taken out the API Key and latitude longitude and set them to variables..."https://api.darksky.net/forecast/f5d3eda07bc28ebd39b109bd0a11d91b/37.8267,-122.4233"

    //Check to see that a network connection is available before making a network call
    if (isNetworkAvailable()) {

        toggleRefresh();

        OkHttpClient client = new OkHttpClient();
        Request request = new Request.Builder()
                .url(forecastUrl)
                .build();

        Call call = client.newCall(request);
        //Use callback as the main line of communication between the main thread and the background worker thread(asynchronous thread).
        // After the worker has performed, If there is an issue, the onFailure method will be called and if the callback is valid then the onResponse will be called

        call.enqueue(new Callback() {

            @Override
            public void onFailure(/*Call call*/Request request, IOException e) {

             //Refresh the data...Must be run on UI thread.
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        toggleRefresh();
                    }

                });
                alertUserAboutError();
            }

            @Override
            public void onResponse(/*Call call, */Response response) throws IOException {
                //Needed to request internet connection permission in the Android Manifest

                //Refresh the data...Must be run on UI thread.
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        toggleRefresh();
                    }
                });

                try {
                    String jsonData = response.body().string();
                    Log.v(TAG, jsonData);
                    if (response.isSuccessful()) {
                     //   Log.v(TAG, response.body().string());
                        mCurrentWeather = getCurrentDetails(jsonData);
                        runOnUiThread(new Runnable() {
                            @Override
                            public void run() {
                                updateDisplay();
                            }
                        });

                    } else {
                        alertUserAboutError();
                    }
                } catch (IOException e) {
                    Log.e(TAG, "Exception caught: ", e);
                } catch (JSONException e) {
                    Log.e(TAG, "Exception caught: ", e);
                }

            }
        }); //end of callback


    } //end of network check conditional
     else {
        Toast.makeText(this, R.string.network_unavailable_message, Toast.LENGTH_LONG).show(); //Test network issues with airplane mode in emulator
    }
}

private void toggleRefresh() { //called for each onFailure, OnResponse and networkIsAvailable
    if (mProgressBar.getVisibility() == View.INVISIBLE) {
        mProgressBar.setVisibility(View.VISIBLE); //Will superimpose the progressbar on top of the refresh button. It will show only when we get new data
        mRefreshImageView.setVisibility(View.INVISIBLE); //Refresh will be invisible when progress is visible
    }
    else {
        mProgressBar.setVisibility(View.INVISIBLE);
        mRefreshImageView.setVisibility(View.VISIBLE);
    }
}

//NOTE: ONLY MAIN THREAD IS ALLOWED TO UPDATE USER INTFERFACE...
   //We use ACTIVITY.runOnUIThread( runnable object) to tell the main UI thread that we have code ready for it.
private void updateDisplay() {
    mTemperatureLabel.setText(mCurrentWeather.getTemperature() + "");
    mTimeLabel.setText("At " + mCurrentWeather.getFormattedTime() + " it will be");
    mHumidityValue.setText(mCurrentWeather.getHumidity() + "");
    mPrecipValue.setText(mCurrentWeather.getPrecipChance() + "%");
    mSummaryLabel.setText(mCurrentWeather.getSummary());

    Drawable drawable = ContextCompat.getDrawable(this, mCurrentWeather.getIconId());
    mIconImageView.setImageDrawable(drawable);
}

private CurrentWeather getCurrentDetails(String jsonData)  throws JSONException {
    JSONObject forecast = new JSONObject(jsonData);
    String timezone = forecast.getString("timezone");
    Log.i(TAG, "From JSON:" + timezone);

    JSONObject currently = forecast.getJSONObject("currently");

     CurrentWeather currentWeather = new CurrentWeather();

    currentWeather.setHumidity(currently.getDouble("humidity"));
    currentWeather.setTime(currently.getLong("time"));
    currentWeather.setIcon(currently.getString("icon"));
    currentWeather.setPrecipChance(currently.getDouble("precipProbability"));
    currentWeather.setSummary(currently.getString("summary"));
    currentWeather.setTemperature(currently.getDouble("temperature"));
    currentWeather.setTimeZone(timezone);

    //display the formatted time in the blog, as it should appear in the app
    Log.d(TAG, currentWeather.getFormattedTime());
    return new CurrentWeather();
}

private boolean isNetworkAvailable() {
    ConnectivityManager manager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE); //parameter is the name of service we want in either string format or referenced through the context CLASS as seen.

    NetworkInfo networkInfo = manager.getActiveNetworkInfo();
    //this also needs permission in the Android Manifest

   boolean isAvailable = false;
   if (networkInfo !=null && networkInfo.isConnected()){
       isAvailable = true;
   }
   return isAvailable;
}

private void alertUserAboutError() {
    AlertDialogFragment dialog = new AlertDialogFragment();

    dialog.show(getFragmentManager(), "error_dialog");  //this will show dialog and assigning a string tag to it
}