anchor.diff:  { pythonPackages, fetchurl, stdenv }:
   
   rec {
  -  BTrees = pythonPackages.buildPythonPackage {
  -    name = "BTrees-4.3.1";
  -    src = fetchurl {
  -      url = "https://pypi.python.org/packages/24/76/cd6f225f2180c22af5cdb6656f51aec5fca45e45bdc4fa75c0a32f161a61/BTrees-4.3.1.tar.gz";
  -      sha256 = "2565b7d35260dfc6b1e2934470fd0a2f9326c58c535a2b4cb396289d1c195a95";
  -    };
  -    propagatedBuildInputs = [
  -      persistent
  -      transaction
  -    ] ++ (with pythonPackages; [ zope_interface coverage ]);
  -
  -    meta = with stdenv.lib; {
  -      homepage = "";
  -      license = licenses.zpt21;
  -      description = "Scalable persistent object containers";
  -    };
  -  };
  -
  -  ZConfig = pythonPackages.buildPythonPackage {
  -    name = "ZConfig-3.1.0";
  -    src = fetchurl {
  -      url = "https://pypi.python.org/packages/52/b3/a96d62711a26d8cfbe546519975dc9ed54d2eb50b3238d2e6de045764796/ZConfig-3.1.0.tar.gz";
  -      sha256 = "c21fa3a073a56925a8098036d46717392994a92cffea1b3cda3176b70c0a842e";
  -    };
  -    propagatedBuildInputs = with pythonPackages; [ zope_testrunner ];
  -    meta = with stdenv.lib; {
  -      homepage = "";
  -      license = licenses.zpt21;
  -      description = "Structured Configuration Library";
  -    };
  -  };
  -
     zodb = pythonPackages.buildPythonPackage {
       name = "ZODB-5.2.0";
       src = fetchurl {
  
positive.code:     };
      doCheck = false;
      propagatedBuildInputs = [
        BTrees
        persistent
        transaction
        ZConfig
        zc.lockfile
        zodbpickle
      ] ++ (with pythonPackages; [ six wheel zope_interface ]);
      meta = with stdenv.lib; {
        homepage = "";
        license = licenses.zpt21;
        description = "Zope Object Database: object database and persistence";
      };
    };
  
    persistent = pythonPackages.buildPythonPackage {
      name = "persistent-4.2.2";
      src = fetchurl {
        url = "https://pypi.python.org/packages/3d/71/3302512282b606ec4d054e09be24c065915518903b29380b6573bff79c24/persistent-4.2.2.tar.gz";
        sha256 = "52ececc6dbba5ef572d3435189318b4dff07675bafa9620e32f785e147c6563c";
      };
      propagatedBuildInputs = with pythonPackages; [ zope_interface six wheel ];
      meta = with stdenv.lib; {
        homepage = "";
        license = licenses.zpt21;
        description = "Translucent persistent objects";
      };
    };
  
  
negative.code:       url = "https://pypi.python.org/packages/8c/af/3ffafe85bcc93ecb09459f3f2bd8fbe142e9ab34048f9e2774543b470cbd/transaction-2.0.3.tar.gz";
        sha256 = "67bfb81309ba9717edbb2ca2e5717c325b78beec0bf19f44e5b4b9410f82df7f";
      };
      propagatedBuildInputs = with pythonPackages; [
        zope_interface
        six
        wheel
        mock
      ];
      meta = with stdenv.lib; {
        homepage = "";
        license = licenses.zpt21;
        description = "Transaction management for Python";
      };
    };
  }
  