anchor.diff:    };
   
     docker_compose = buildPythonPackage rec {
  -    name = "docker-compose-1.2.0rc2";
  +    version = "1.4.0";
  +    name = "docker-compose-${version}";
  +    namePrefix = "";
       disabled = isPy3k || isPyPy;
   
       src = pkgs.fetchurl {
         url = "https://pypi.python.org/packages/source/d/docker-compose/${name}.tar.gz";
  -      md5 = "311ec5023e51097ca3acbf37fac062bd";
  +      md5 = "a93e801ebe829c2f869cb23d0b606272";
       };
   
       propagatedBuildInputs = with self; [
  -      six requests pyyaml texttable docopt docker
  +      six requests pyyaml texttable docopt docker dockerpty websocket_client
         (requests2.override {
           src = pkgs.fetchurl {
  -          url = "https://pypi.python.org/packages/source/r/requests/requests-2.5.3.tar.gz";
  -          md5 = "23bf4fcc89ea8d353eb5353bb4a475b1";
  -        };
  -      })
  -      (dockerpty.override {
  -        src = pkgs.fetchurl {
  -          url = "https://pypi.python.org/packages/source/d/dockerpty/dockerpty-0.3.2.tar.gz";
  -          md5 = "1f97b24d2f4b2c345f176f91655002dd";
  -        };
  -      })
  -      (websocket_client.override {
  -        src = pkgs.fetchurl {
  -          url = "https://pypi.python.org/packages/source/w/websocket-client/websocket-client-0.11.0.tar.gz";
  -          md5 = "fcffbb5ac10941d9ace416d14d1e3ec8";
  +          url = "https://pypi.python.org/packages/source/r/requests/requests-2.6.1.tar.gz";
  +          md5 = "da6e487f89e6a531699b7fd97ff182af";
           };
         })
       ];
  
positive.code: 
  
    websocket_client = buildPythonPackage rec {
      name = "websocket-client-0.17.0";
  
      src = pkgs.fetchurl {
        url = "https://pypi.python.org/packages/source/w/websocket-client/${name}.tar.gz";
        md5 = "c86591719085eaf4a01c2275e0c834fc";
      };
  
      propagatedBuildInputs = with self; [ six backports_ssl_match_hostname_3_4_0_2 unittest2 argparse ];
  
negative.code:   };
  
    docker = buildPythonPackage rec {
      name = "docker-py-1.3.1";
  
      src = pkgs.fetchurl {
        url = "https://pypi.python.org/packages/source/d/docker-py/${name}.tar.gz";
        md5 = "07a5f41fd3f8cc72d05deed628700e99";
      };
  
      propagatedBuildInputs = with self; [ six requests websocket_client ];
  