     // power up
     public func powerOn(afterPowerOn:(()->())?, afterPowerOff:(()->())? = nil) {
         Logger.debug("powerOn")
-        self.afterPowerOnCallback = afterPowerOn
-        self.afterPowerOffCallback = afterPowerOff
-        if self.poweredOn() && self.afterPowerOnCallback != nil {
-            asyncCallback(self.afterPowerOnCallback!)
+        self.afterPowerOn = afterPowerOn
+        self.afterPowerOff = afterPowerOff
+        if self.poweredOn() && self.afterPowerOn != nil {
+            asyncCallback(self.afterPowerOn!)
         }
     }
 

public class CentralManager : NSObject, CBCentralManagerDelegate {
    
    // PRIVATE
    private var afterPowerOnCallback                : (()->())?
    private var afterPowerOffCallback               : (()->())?
    private var afterPeripheralDiscoveredCallback   : ((peripheral:Peripheral, rssi:Int)->())?

    private let cbCentralManager    : CBCentralManager!


            break
        case .PoweredOff:
            Logger.debug("CentralManager#centralManagerDidUpdateState: PoweredOff")
            if let afterPowerOff = self.afterPowerOff {
                self.asyncCallback(afterPowerOff)
            }
            break
        case .PoweredOn:
            Logger.debug("CentralManager#centralManagerDidUpdateState: PoweredOn")
            if let afterPowerOn = self.afterPowerOn {
                self.asyncCallback(afterPowerOn)
            }
            break
        }
