anchor.diff:  { lib
   , buildPythonPackage
  +, pythonOlder
   , fetchFromGitHub
   , requests
  -, urllib3
  +, six
  +, stone
   , mock
  -, setuptools
  -, stone
  -, pythonOlder
  +, pytest-mock
  +, pytestCheckHook
   }:
   
   buildPythonPackage rec {
  
positive.code:       --replace "'pytest-runner == 5.2.0'," ""
    '';
  
    # Set DROPBOX_TOKEN environment variable to a valid token.
    doCheck = false;
  
    pythonImportsCheck = [
      "dropbox"
    ];
  
    meta = with lib; {
  
negative.code:     owner = "dropbox";
      repo = "dropbox-sdk-python";
      rev = "v${version}";
      hash = "sha256-pq/LkyOCS0PnujfN9aIx42aeZ8tw4XvRQ4Vid/nXgWE=";
    };
  
    propagatedBuildInputs = [
      requests
      six
      stone
    ];
  
    checkInputs = [
      mock
      pytest-mock
      pytestCheckHook
    ];
  
    postPatch = ''
  