anchor.diff:  
   
   
  -    "six" = python.mkDerivation {
  -      name = "six-1.11.0";
  -      src = pkgs.fetchurl { url = "https://pypi.python.org/packages/16/d8/bc6316cf98419719bd59c91742194c111b6f2e85abac88e496adefaf7afe/six-1.11.0.tar.gz"; sha256 = "70e8a77beed4562e7f14fe23a786b54f6296e34344c23bc42f07b15018ff98e9"; };
  -      doCheck = commonDoCheck;
  -      buildInputs = commonBuildInputs;
  -      propagatedBuildInputs = [ ];
  -      meta = with pkgs.stdenv.lib; {
  -        homepage = "http://pypi.python.org/pypi/six/";
  +    "requests" = python.mkDerivation {
  +      name = "requests-2.18.4";
  +      src = pkgs.fetchurl { url = "https://pypi.python.org/packages/b0/e1/eab4fc3752e3d240468a8c0b284607899d2fbfb236a56b7377a329aa8d09/requests-2.18.4.tar.gz"; sha256 = "9c443e7324ba5b85070c4a818ade28bfabedf16ea10206da1132edaa6dda237e"; };
  +      doCheck = commonDoCheck;
  +      buildInputs = commonBuildInputs;
  +      propagatedBuildInputs = [
  +      self."certifi"
  +      self."chardet"
  +      self."idna"
  +      self."urllib3"
  +    ];
  +      meta = with pkgs.stdenv.lib; {
  +        homepage = "http://python-requests.org";
  +        license = licenses.asl20;
  +        description = "Python HTTP for Humans.";
  +      };
  +    };
  +
  +
  +
  +    "requests-oauthlib" = python.mkDerivation {
  +      name = "requests-oauthlib-0.8.0";
  +      src = pkgs.fetchurl { url = "https://pypi.python.org/packages/80/14/ad120c720f86c547ba8988010d5186102030591f71f7099f23921ca47fe5/requests-oauthlib-0.8.0.tar.gz"; sha256 = "883ac416757eada6d3d07054ec7092ac21c7f35cb1d2cf82faf205637081f468"; };
  +      doCheck = commonDoCheck;
  +      buildInputs = commonBuildInputs;
  +      propagatedBuildInputs = [
  +      self."oauthlib"
  +      self."requests"
  +    ];
  +      meta = with pkgs.stdenv.lib; {
  +        homepage = "https://github.com/requests/requests-oauthlib";
  +        license = licenses.bsdOriginal;
  +        description = "OAuthlib authentication support for Requests.";
  +      };
  +    };
  +
  +
  +
  +    "urllib3" = python.mkDerivation {
  +      name = "urllib3-1.22";
  +      src = pkgs.fetchurl { url = "https://pypi.python.org/packages/ee/11/7c59620aceedcc1ef65e156cc5ce5a24ef87be4107c2b74458464e437a5d/urllib3-1.22.tar.gz"; sha256 = "cc44da8e1145637334317feebd728bd869a35285b93cbb4cca2577da7e62db4f"; };
  +      doCheck = commonDoCheck;
  +      buildInputs = commonBuildInputs;
  +      propagatedBuildInputs = [
  +      self."certifi"
  +      self."idna"
  +    ];
  +      meta = with pkgs.stdenv.lib; {
  +        homepage = "https://urllib3.readthedocs.io/";
           license = licenses.mit;
  -        description = "Python 2 and 3 compatibility utilities";
  -      };
  -    };
  -
  -
  -
  -    "transaction" = python.mkDerivation {
  -      name = "transaction-2.1.2";
  -      src = pkgs.fetchurl { url = "https://pypi.python.org/packages/27/c5/27f1953db67de21832fd977684e639e41c7738dc449886419bb2aa235094/transaction-2.1.2.tar.gz"; sha256 = "b9bc365e7dba3877e0f6fdee32aa029b8c0c1eb4fe227f524bffd5fc46064bd5"; };
  -      doCheck = commonDoCheck;
  -      buildInputs = commonBuildInputs;
  -      propagatedBuildInputs = [
  -      self."zope.interface"
  -    ];
  -      meta = with pkgs.stdenv.lib; {
  -        homepage = "https://github.com/zopefoundation/transaction";
  -        license = licenses.zpl21;
  -        description = "Transaction management for Python";
  -      };
  -    };
  -
  -
  -
  -    "validators" = python.mkDerivation {
  -      name = "validators-0.12.0";
  -      src = pkgs.fetchurl { url = "https://pypi.python.org/packages/8f/b5/9c9bf9cc9b50acea54a175eee97b0092f7676dbd6a17e00591588640acc3/validators-0.12.0.tar.gz"; sha256 = "bf1aa66554df0a7907f0e78b6d356e2ce30d6f2e73fefd1f3b14d20114341066"; };
  -      doCheck = commonDoCheck;
  -      buildInputs = commonBuildInputs;
  -      propagatedBuildInputs = [
  -      self."decorator"
  -      self."six"
  -    ];
  -      meta = with pkgs.stdenv.lib; {
  -        homepage = "https://github.com/kvesteri/validators";
  -        license = licenses.bsdOriginal;
  -        description = "Python Data Validation for Humans™.";
  -      };
  -    };
  -
  -
  -
  -    "zope.interface" = python.mkDerivation {
  -      name = "zope.interface-4.4.3";
  -      src = pkgs.fetchurl { url = "https://pypi.python.org/packages/bd/d2/25349ed41f9dcff7b3baf87bd88a4c82396cf6e02f1f42bb68657a3132af/zope.interface-4.4.3.tar.gz"; sha256 = "d6d26d5dfbfd60c65152938fcb82f949e8dada37c041f72916fef6621ba5c5ce"; };
  -      doCheck = commonDoCheck;
  -      buildInputs = commonBuildInputs;
  -      propagatedBuildInputs = [ ];
  -      meta = with pkgs.stdenv.lib; {
  -        homepage = "https://github.com/zopefoundation/zope.interface";
  -        license = licenses.zpl21;
  -        description = "Interfaces for Python";
  -      };
  -    };
  -
  -
  -
  -    "zope.sqlalchemy" = python.mkDerivation {
  -      name = "zope.sqlalchemy-0.7.7";
  -      src = pkgs.fetchurl { url = "https://pypi.python.org/packages/14/95/47ef5f5fbf5f18dc95d6d39b7dbd690818b541afa724d14ed176e415b134/zope.sqlalchemy-0.7.7.tar.gz"; sha256 = "5da8ff6b060f3a47fc0cbc61cfd6a83b959b5e730f95e492edcf7b9bf3ec987a"; };
  -      doCheck = commonDoCheck;
  -      buildInputs = commonBuildInputs;
  -      propagatedBuildInputs = [
  -      self."SQLAlchemy"
  -      self."transaction"
  -      self."zope.interface"
  -    ];
  -      meta = with pkgs.stdenv.lib; {
  -        homepage = "http://pypi.python.org/pypi/zope.sqlalchemy";
  -        license = licenses.zpl21;
  -        description = "Minimal Zope/SQLAlchemy transaction integration";
  +        description = "HTTP library with thread-safe connection pooling, file post, and more.";
         };
       };
   
  
positive.code: 
    generated = self: {
  
      "Jinja2" = python.mkDerivation {
        name = "Jinja2-2.10";
        src = pkgs.fetchurl { url = "https://pypi.python.org/packages/56/e6/332789f295cf22308386cf5bbd1f4e00ed11484299c5d7383378cf48ba47/Jinja2-2.10.tar.gz"; sha256 = "f84be1bb0040caca4cea721fcbbbbd61f9be9464ca236387158b0feea01914a4"; };
        doCheck = commonDoCheck;
        buildInputs = commonBuildInputs;
        propagatedBuildInputs = [
        self."MarkupSafe"
      ];
        meta = with pkgs.stdenv.lib; {
          homepage = "http://jinja.pocoo.org/";
          license = licenses.bsdOriginal;
          description = "A small but fast and easy to use stand-alone template engine written in pure python.";
        };
      };
  
  
  
      "MarkupSafe" = python.mkDerivation {
        name = "MarkupSafe-1.0";
        src = pkgs.fetchurl { url = "https://pypi.python.org/packages/4d/de/32d741db316d8fdb7680822dd37001ef7a448255de9699ab4bfcbdf4172b/MarkupSafe-1.0.tar.gz"; sha256 = "a6be69091dac236ea9c6bc7d012beab42010fa914c459791d627dad4910eb665"; };
        doCheck = commonDoCheck;
        buildInputs = commonBuildInputs;
        propagatedBuildInputs = [ ];
        meta = with pkgs.stdenv.lib; {
          homepage = "http://github.com/pallets/markupsafe";
          license = licenses.bsdOriginal;
          description = "Implements a XML/HTML/XHTML Markup safe string for Python";
        };
      };
  
  
  
      "PyYAML" = python.mkDerivation {
        name = "PyYAML-3.12";
        src = pkgs.fetchurl { url = "https://pypi.python.org/packages/4a/85/db5a2df477072b2902b0eb892feb37d88ac635d36245a72a6a69b23b383a/PyYAML-3.12.tar.gz"; sha256 = "592766c6303207a20efc445587778322d7f73b161bd994f227adaa341ba212ab"; };
        doCheck = commonDoCheck;
        buildInputs = commonBuildInputs;
        propagatedBuildInputs = [ ];
        meta = with pkgs.stdenv.lib; {
          homepage = "http://pyyaml.org/wiki/PyYAML";
          license = licenses.mit;
          description = "YAML parser and emitter for Python";
        };
      };
  
  
  
      "SQLAlchemy" = python.mkDerivation {
        name = "SQLAlchemy-1.1.15";
        src = pkgs.fetchurl { url = "https://pypi.python.org/packages/c2/f6/11fcc1ce19a7cb81b1c9377f4e27ce3813265611922e355905e57c44d164/SQLAlchemy-1.1.15.tar.gz"; sha256 = "8b79a5ed91cdcb5abe97b0045664c55c140aec09e5dd5c01303e23de5fe7a95a"; };
        doCheck = commonDoCheck;
        buildInputs = commonBuildInputs;
        propagatedBuildInputs = [
        self."psycopg2"
      ];
        meta = with pkgs.stdenv.lib; {
          homepage = "http://www.sqlalchemy.org";
          license = licenses.mit;
          description = "Database Abstraction Library";
        };
      };
  
  
  
      "SQLAlchemy-Searchable" = python.mkDerivation {
        name = "SQLAlchemy-Searchable-0.10.6";
        src = pkgs.fetchurl { url = "https://pypi.python.org/packages/77/7c/e767325f3a666095fda7f97cd611c6ab47b27d23c9db8bf3b755f0d2e8a3/SQLAlchemy-Searchable-0.10.6.tar.gz"; sha256 = "84f0bff434a17d64e8f7f394065b21855bd3c8a3ede770a25c84127e5d0f95f7"; };
        doCheck = commonDoCheck;
        buildInputs = commonBuildInputs;
        propagatedBuildInputs = [
        self."SQLAlchemy"
        self."SQLAlchemy-Utils"
        self."psycopg2"
        self."pyparsing"
        self."validators"
      ];
        meta = with pkgs.stdenv.lib; {
          homepage = "https://github.com/kvesteri/sqlalchemy-searchable";
          license = licenses.bsdOriginal;
          description = "Provides fulltext search capabilities for declarative SQLAlchemy models.";
        };
      };
  
  
  
      "SQLAlchemy-Utils" = python.mkDerivation {
        name = "SQLAlchemy-Utils-0.32.21";
        src = pkgs.fetchurl { url = "https://pypi.python.org/packages/6b/8c/bf6539a85705e845e9f83908cc290dd34c352d90d9a86134124bd4b64acd/SQLAlchemy-Utils-0.32.21.tar.gz"; sha256 = "e35431b0e57c4f7030ff598c23813c8b7b04b508ce10e8e9ebe448645b38d6d7"; };
        doCheck = commonDoCheck;
        buildInputs = commonBuildInputs;
        propagatedBuildInputs = [
        self."Jinja2"
        self."SQLAlchemy"
        self."psycopg2"
        self."six"
      ];
        meta = with pkgs.stdenv.lib; {
          homepage = "https://github.com/kvesteri/sqlalchemy-utils";
          license = licenses.bsdOriginal;
          description = "Various utility functions for SQLAlchemy.";
        };
      };
  
  
  
      "WebOb" = python.mkDerivation {
        name = "WebOb-1.7.4";
        src = pkgs.fetchurl { url = "https://pypi.python.org/packages/75/34/731e23f52371852dfe7490a61644826ba7fe70fd52a377aaca0f4956ba7f/WebOb-1.7.4.tar.gz"; sha256 = "8d10af182fda4b92193113ee1edeb687ab9dc44336b37d6804e413f0240d40d9"; };
  
negative.code:       doCheck = commonDoCheck;
        buildInputs = commonBuildInputs;
        propagatedBuildInputs = [
        self."WebOb"
        self."dectate"
        self."importscan"
  