anchor.diff:      })
     ];
   
  +  checkInputs = [
  +    nose
  +  ];
  +
     propagatedBuildInputs = [
       six
     ];
  
positive.code:   # circular dependency anytree → graphviz → pango → glib → gtk-doc → anytree
    doCheck = withGraphviz;
  
    checkInputs = [ pytestCheckHook nose ];
  
    pytestFlagsArray = lib.optionals (pythonOlder "3.4") [
      # Use enums, which aren't available pre-python3.4
      "--ignore=tests/test_resolver.py"
      "--ignore=tests/test_search.py"
    ];
  
    meta = with lib; {
      description = "Powerful and Lightweight Python Tree Data Structure";
  
negative.code: { lib
  , buildPythonPackage
  , fetchPypi
  , substituteAll
  , fetchpatch
  , nose
  , six
  , withGraphviz ? true
  , graphviz
  , fontconfig
  }:
  
  buildPythonPackage rec {
  