     }
     
     private func connectKnownPeers() {
-        self.ensure(centralManagerHasState: .poweredOn) { result in
+        self.once(manager: centralManager, hasState: .poweredOn, invoke: { result in
             switch result {
             case .error(let err):
                 self.publish(notification: .error(err))

            timeOfLastUpdateCharacteristic
        ]
        
        self.ensure(peripheralManagerHasState: .poweredOn) { result in
            switch result {
            case .error(let err): self.publish(notification: .error(err))
            case .success:
                self.peripheralManager.add(service)
                self.connectKnownPeers()
            }
        }
    }
    
    /**

                    self.connect(peerWithId: peripheralId)
                }
            }
        })
    }
    
    fileprivate func publish(notification: Clink.Notification) {
