Byte Array to NSData

gistfile1.txt

// This goes in an NSData extension
convenience init (byteArray: [NSNumber]) {
  let bytes = byteArray.combine([]) {
    (n, inout b: [Byte], _, _) in
    b.append(n.unsignedCharValue)
  }
  self.init(bytes: bytes, length: bytes.count)
}