 public extension Cusp {
 
 	/**
-	scan for BLE peripherals(扫描从设备)
-
-	- parameter advertisingServiceUUIDs: an array containing specific UUIDs, set nil to scan for all available peripherals(目标从设备的广播服务UUID数组, 如传nil则扫描所有从设备)
-	- parameter duration:                scan duration, default is 3.0(扫描时长, 默认3.0秒)
-	- parameter completion:              a closure called right after scan timed out(扫描完成后的回调, 返回从设备数组)
-	- parameter abruption:               a closure called when scan is abrupted(扫描中断的回调, 返回错误原因)
+	Scan for BLE peripherals of specific advertising service UUIDs. If pass nil, all kinds of peripheral will be scanned. A timed-out scan will call completion closure, or else the abruption one.
+	根据UUID数组扫描指定从设备, 如不指定UUID, 则扫描任意从设备. 扫描成功会执行completion闭包, 反之则执行abruption闭包;
+
+	- parameter advertisingServiceUUIDs: a specific UUID array or nil. 指定的广播服务UUID数组或nil
+	- parameter duration:                scan duration in second, 3.0s by default. 扫描时长, 默认3.0秒
+	- parameter completion:              a closure called when scan timed out. 扫描完成后的回调, 返回从设备数组
+	- parameter abruption:               a closure called when scan is abrupted. 扫描中断的回调, 返回错误原因
 	*/
 	public func scanForUUID(advertisingServiceUUIDs: [UUID]?, duration: NSTimeInterval = defaultDuration, completion: (([Peripheral]) -> Void)?, abruption: ((NSError) -> Void)?) {
 


extension Cusp {

	private func checkIn(request: ScanRequest) -> Void {
		self.scanRequests.insert(request)


		}
	}

	/**
	Extract target UUIDs from existed scan requests and union them.

	- returns: a new UUID array after union
	*/
	private func restructureTarget() -> [UUID]? {
		var targets = Set<UUID>()
		for req in self.scanRequests {
