anchor.diff:    # circular dependencies if enabled by default
     doCheck = false;
   
  -  checkInputs = [ pytestCheckHook xmltodict nbconvert ipywidgets ];
  +  checkInputs = [
  +    ipykernel
  +    ipywidgets
  +    nbconvert
  +    pytest-asyncio
  +    pytestCheckHook
  +    xmltodict
  +  ];
   
     preCheck = ''
       export HOME=$(mktemp -d)
  
positive.code: 
    disabled = pythonOlder "3.7";
  
    src = fetchPypi {
      inherit pname version;
      hash = "sha256-uAcm/B+4mg6Pi+HnfijQAmsejtkLwUPIoMdiLk+M3Z4=";
    };
  
    propagatedBuildInputs = [ async_generator traitlets nbformat nest-asyncio jupyter-client ];
  
negative.code: { async_generator
  , buildPythonPackage
  , fetchFromGitHub
  , ipykernel
  , ipywidgets
  , jupyter-client
  , lib
  , nbconvert
  , nbformat
  , nest-asyncio
  , pytest-asyncio
  , pytestCheckHook
  , pythonOlder
  , traitlets
  , xmltodict
  }:
  
  let nbclient = buildPythonPackage rec {
  