     }
 
     private class func allowedCharacterSet() -> NSMutableCharacterSet {
-        let characterSet = NSCharacterSet.URLQueryAllowedCharacterSet().mutableCopy() as NSMutableCharacterSet
+        let characterSet = NSCharacterSet.URLQueryAllowedCharacterSet().mutableCopy() as! NSMutableCharacterSet
         characterSet.removeCharactersInString("/")
         return characterSet
     }


            var output = encodeCoordinate(coordinates[0].latitude) + encodeCoordinate(coordinates[0].longitude)

            for var i = 1; i < countElements(coordinates); ++i {
                let a = coordinates[i]
                let b = coordinates[i - 1]
                output += encodeCoordinate(a.latitude - b.latitude)

            requestString = "pin-"
            requestString += size.rawValue

            if (count(label) > 0) {
                requestString += "-" + label
            }

