 
     // ServiceImpl
     
-    
     private var cbCentralManager : CBCentralManager! = nil
     private let centralQueue     = dispatch_queue_create("com.gnos.us.central.main", DISPATCH_QUEUE_SERIAL)
     

        return self._isScanning
    }
    
    public func startScanning(central:Wrapper, capacity:Int? = nil) -> FutureStream<Wrapper.WrappedPeripheral> {
        return self.startScanningForServiceUUIDs(central, uuids:nil, capacity:capacity)
    }
    
    public func startScanningForServiceUUIDs(central:Wrapper, uuids:[CBUUID]!, capacity:Int? = nil) -> FutureStream<Wrapper.WrappedPeripheral> {
        if !self._isScanning {
            Logger.debug("CentralManagerImpl#startScanningForServiceUUIDs: \(uuids)")
            self._isScanning = true

    
    // connection
    public func disconnectAllPeripherals() {
        self.impl.disconnectAllPeripherals()
    }
    
    // power up
    public func powerOn() -> Future<Void> {
        return self.impl.powerOn()
    }
    
    public func powerOff() -> Future<Void> {
        return self.impl.powerOff()
    }
    
    // CBCentralManagerDelegate
