anchor.diff:    propagatedBuildInputs = [
       dateutil
       six
  +    text-unidecode
     ] ++ lib.optional (pythonOlder "3.3") ipaddress;
   
     meta = with lib; {
  
positive.code: { lib, buildPythonPackage, fetchPypi, pythonOlder,
    # Build inputs
    dateutil, six, ipaddress ? null,
    # Test inputs
    email_validator, nose, mock, ukpostcodeparser }:
  
  
negative.code: 
  buildPythonPackage rec {
    pname = "Faker";
    version = "0.8.11";
  
    src = fetchPypi {
      inherit pname version;
      sha256 = "126kdy6lj10rwgchzz0lzjabx0zcyskamhn0qib67k69fcksjmq8";
    };
  
    checkInputs = [
  