http://stackoverflow.com/questions/30255402/swift-how-to-convert-a-string-to-uint8-array
let str = "test" byteArray [UInt8](str.utf8)
http://stackoverflow.com/questions/30255402/swift-how-to-convert-a-string-to-uint8-array
let str = "test" byteArray [UInt8](str.utf8)