             }
         case .leftTop:
             attributes.center = CGPoint.init(x: cellSize.width/2.0,
-                                             y: (contentOffset?.y)!)
+                                             y: (contentOffset.y))
             
             if (angle <= (M_PI_2+2.0*angleOffset+angular/90.0)) && (angle >= -angleOffset) {
                 attributes.isHidden = false

        switch configuration.wheelType {
        case .leftBottom:
            attributes.center = CGPoint.init(x: cellSize.width/2.0,
                                             y: (contentOffset?.y)!+(viewSize?.height)!-cellSize.height/2)
            
            if (angle <= (M_PI_2+2.0*angleOffset+angular/90.0)) && (angle >= -angleOffset) {
                attributes.isHidden = false

            }
            
        case .rightCenter:
            attributes.center = CGPoint.init(x: (viewSize.width)-cellSize.width/2.0,
                                             y: (contentOffset.y)+(viewSize.height)/2)
            
            if (angle <= (M_PI+2.0*angleOffset+angular/180.0)) && (angle >= -angleOffset) {
                attributes.isHidden = false
