func example(fileData:Data){
let pointer = UnsafeMutablePointer<UInt8>.allocate(capacity: fileData.bytes.count)
        
        pointer.initialize(from: fileData.bytes.map{ byte in
            print(byte)
            return UInt8(byte)} , count: fileData.bytes.count)
        defer{
            pointer.deinitialize(count: fileData.bytes.count)
            pointer.deallocate()
        }
}