anchor.diff: -{ lib, buildPythonPackage, fetchPypi, isPy27, idna, typing ? null }:
  +{ lib
  +, buildPythonPackage
  +, fetchPypi
  +, isPy27
  +, idna
  +, typing ? null
  +}:
   
   buildPythonPackage rec {
     pname = "hyperlink";
  
positive.code: 
    src = fetchPypi {
      inherit pname version;
      sha256 = "427af957daa58bc909471c6c40f74c5450fa123dd093fc53efd2e91d2705a56b";
    };
  
    propagatedBuildInputs = [ idna ]
  
negative.code: 
    meta = with lib; {
      description = "A featureful, correct URL for Python";
      homepage = "https://github.com/python-hyper/hyperlink";
      license = licenses.mit;
      platforms = platforms.all;
      maintainers = with maintainers; [ apeschar ];
  