                 @unknown default:
                     let batteryLevel: Float = UIDevice.current.batteryLevel
                     if batteryLevel < 0.15 {
-                        self._positionLocationManager.trackingDesiredAccuracyActive = kCLLocationAccuracyThreeKilometers
-                        self._positionLocationManager.trackingDesiredAccuracyBackground = kCLLocationAccuracyThreeKilometers
+                        _positionLocationManager.trackingDesiredAccuracyActive = kCLLocationAccuracyThreeKilometers
+                        _positionLocationManager.trackingDesiredAccuracyBackground = kCLLocationAccuracyThreeKilometers
                     } else {
-                        self._positionLocationManager.trackingDesiredAccuracyActive = kCLLocationAccuracyHundredMeters
-                        self._positionLocationManager.trackingDesiredAccuracyBackground = kCLLocationAccuracyKilometer
+                        _positionLocationManager.trackingDesiredAccuracyActive = kCLLocationAccuracyHundredMeters
+                        _positionLocationManager.trackingDesiredAccuracyBackground = kCLLocationAccuracyKilometer
                     }
                     break
             }

    ///
    /// - Parameter observer: Observing instance.
    public func addAuthorizationObserver(_ observer: PositionAuthorizationObserver) {
        if self._authorizationObservers == nil {
            self._authorizationObservers = NSHashTable.weakObjects()
        }

        if self._authorizationObservers?.contains(observer) == false {
            self._authorizationObservers?.add(observer)
        }
    }


    ///
    /// - Parameter observer: Observing instance.
    public func removeAuthorizationObserver(_ observer: PositionAuthorizationObserver) {
        if _authorizationObservers?.contains(observer) == true {
            _authorizationObservers?.remove(observer)
        }
        if _authorizationObservers?.count == 0 {
            _authorizationObservers = nil
        }
    }

