úΤ NoneWrap an 2 and check for dropped or duplicated sequence IDs.Example: ghci>  [1..10 :: ] >>=  0  ( . ) >>=  [1,2,3,4,5,6,7,8,9,10] ghci>  [5..10 :: ] >>=  0  ( . ) >>=  *** Exception: user error ( {errType = (, lastSeqId = 0, currSeqId = 5}) ghci>  [1..10 :: ] >>=  5  ( . ) >>=  *** Exception: user error ( {errType = !, lastSeqId = 5, currSeqId = 1}) Wrap an 0 to give a sequence ID for each element written.Example: (outStream', getSeqId) <-  1 outStream return $   (addSeqId getSeqId) outStream' Initial sequence IDEFunction applied to each element of the stream to get the sequence ID Error handler to check the sequence of Pass-through of the given streamInitial sequence ID to count the elements of(  5) is the action to run to get the current sequence ID  fold function initial seed output streamOreturns a new stream as well as an IO action to fetch the updated seed value.    seqid-streams-0.4.1System.IO.Streams.SequenceIdSystem.IO.StreamsfromListtoListData.SequenceIdSequenceIdDroppedSequenceIdDuplicatedSystem.IO.Streams.Combinators contramapMsequenceIdInputStreamsequenceIdOutputStreamio-streams-1.3.2.0System.IO.Streams.Internal InputStream seqid-0.4.1 SequenceIdbaseGHC.BaseidfailGHC.ShowshowSequenceIdError OutputStreamghc-prim GHC.TypesIO outputFoldM