anchor.diff:  
       src = pkgs.fetchurl {
         url = "http://pypi.python.org/packages/source/m/mysql-connector-repackaged/${name}.tar.gz";
  -      md5 = "0b17ad1cb3fe763fd44487cb97cf45b2";
  +      sha256 = "170fbf11c54def1b5fcc919be0a890b760bb2eca81f56123a5dda0c69b5b099e";
       };
   
       meta = {
  
positive.code: 
      src = pkgs.fetchurl {
        url = "https://pypi.python.org/packages/source/w/websocket-client/${name}.tar.gz";
        md5 = "b07a897511a3c585251fe2ea85a9d9d9";
      };
  
      propagatedBuildInputs = with self; [ six backports_ssl_match_hostname_3_4_0_2 unittest2 argparse ];
  
negative.code: 
      src = pkgs.fetchurl {
        url = "https://pypi.python.org/packages/source/S/SQLAlchemy/${name}.tar.gz";
        sha256 = "9edb47d137db42d57fd26673d6c841e189b1aeb9b566cca908962fcc8448c0bc";
      };
  
      preConfigure = optionalString isPy3k ''
  