// Declare mirrorClient and proximityObserver as class properties
let mirrorClient = MirrorClient(appID: "", appToken: "")
var proximityObserver: EPXProximityObserver!

// Inside you class implementation
// Prepare your customized Poster View
let sneakersBanner = Poster() { p in
            
    p.header = "Exceptional traction\nfrom your first to final mile"
    p.body = "Now 20% off!"
    p.image = .preloaded(path: "shoe_big.jpg")
    
    p.style = PosterStyle() { ps in
        
        ps.imagePosition = Position(horizontal: .center, vertical: .top(offset: 80))
        ps.textPosition = Position(horizontal: .center, vertical: .bottom(offset: 80))
        ps.textAlign = .center
        ps.headerFontSize = .percent(130)
    }
}
        
// Initialize your Estimote Cloud credentials
let credentials = CloudCredentials(appID: "", appToken: "")

// Build ProximityObserver with Cloud credentials
self.proximityObserver = ProximityObserver(credentials: credentials, onError: { error in
    
    print("\(error)")
})

// Define near proximity zone
let mirrorZone = ProximityZone(tag: "mirror", range: ProximityRange.near)
mirrorZone.onEnter = { zoneContext in
   
    print("Enter mirror")
    self.mirrorClient.display(sneakersBanner, onMirror: zoneContext.deviceIdentifier)
}
mirrorZone.onExit = { zoneContext in
    
    print("Exit mirror")
}

// Start proximity observation
self.proximityObserver.startObserving([mirrorZone])