anchor.diff:  let target = "/home/robert/.bitcoin/blocks/blk00000.dat"
   
   let stream = getByteStream target 
  -readMessages 2 stream
  +readMessages 1 stream
   
  
positive.code:     | x when x = 0xffuy -> int64 (bytesToInt32 bytes.[1 .. 8]), 9
      | _ -> failwith "unexpectedly large byte :)"
  
  
  type Block =
      { Version: int
  
negative.code:           InputTransactionIndex = inputTransactionIndex
            ResponseScriptLength = responseScriptLength
            ResponseScript = responseScript
            SequenceNumber = sequenceNumber
            NumberOfOutputs = numberOfOutputs
            Outputs = Array.ofList outputs }
  
      printfn "%A" block 
  
  