anchor.diff:  , entrypoints
   , tenacity
   , futures
  +, black
   , backports_tempfile
   , isPy27
   , pytest
  
positive.code: , pyyaml
  , nbformat
  , nbconvert
  , six
  , tqdm
  , jupyter_client
  
negative.code:     pyyaml
      nbformat
      nbconvert
      nbclient
      six
      tqdm
      jupyter_client
      requests
      entrypoints
      tenacity
      black
    ] ++ lib.optionals isPy27 [
      futures
      backports_tempfile
  