computeIdentifierHash :: T.Text -> T.Text
computeIdentifierHash documentID =
  T.pack
    $ concatMap (\byte -> let hex = showHex byte ""
                              padding = take (2 - length hex) (repeat '0')
                          in hex ++ padding)
    $ BS.unpack $ BS.take 4
    $ Hash.asByteString $ Hash.hash
    $ T.encodeUtf8 documentID
computeIdentifierHash :: T.Text -> T.Text
computeIdentifierHash documentID =
  T.pack
    $ concatMap (\byte -> let hex = showHex byte ""
                              padding = take (2 - length hex) (repeat '0')
                          in hex ++ padding)
    $ BS.unpack $ BS.take 4
    $ Hash.asByteString $ Hash.hash
    $ T.encodeUtf8 documentID
computeIdentifierHash documentID =
  T.pack
    $ concatMap (\byte -> let hex = showHex byte ""
                              padding = take (2 - length hex) (repeat '0')
                          in hex ++ padding)
    $ BS.unpack $ BS.take 4
    $ Hash.asByteString $ Hash.hash
    $ T.encodeUtf8 documentID