Trying to get name of a city, while having latitude and longitude. 
Inside a model class `Location`, I'm using `reverseGeocodeLocation(location: , completionHandler: )` func that comes with CLGeocoder (part of CoreLocation). 

```
func getLocationName() {

    let geoCoder = CLGeocoder()
    let location = CLLocation(latitude: currentLatitude, longitude: currentLongitude)

    geoCoder.reverseGeocodeLocation(location, completionHandler: { placemarks, error in
        guard let addressDict = placemarks?[0].addressDictionary else {
            return
        }

        if let city = addressDict["City"] as? String {
            self.currentCity = city
            print(city)
        }
        if let zip = addressDict["ZIP"] as? String {
            print(zip)
        }
        if let country = addressDict["Country"] as? String {
            print(country)
        }
    })
}

```

However, in `ViewController`, after running the `getLocationName()`, the `location.currentCity` is `nil`, since the completion handler is async, and wasn't finished yet. 

How can I make sure that the completion handler is finished running so I can access `location.currentCity` ?