anchor.diff:  #
   #  libmusicbrainz2 = callPackage ../development/libraries/libmusicbrainz/2.x.nix { };
   #
  -#  libmusicbrainz3 = callPackage ../development/libraries/libmusicbrainz { };
  -#
  +  libmusicbrainz3 = callPackage ../development/libraries/libmusicbrainz { };
  +
     libmusicbrainz5 = callPackage ../development/libraries/libmusicbrainz/5.x.nix { };
  -#
  -#  libmusicbrainz = libmusicbrainz3;
  +
  +  libmusicbrainz = libmusicbrainz3;
   #
   #  libmwaw = callPackage ../development/libraries/libmwaw { };
   #
  
positive.code: #    libdvdnav = libdvdnav_4_2_1;
  #  } // (config.mplayer or {}));
  #
  #  MPlayerPlugin = browser:
  #    callPackage ../applications/networking/browsers/mozilla-plugins/mplayerplug-in {
  #      inherit browser;
  #      # !!! should depend on MPlayer
  #    };
  #
  #  mrpeach = callPackage ../applications/audio/pd-plugins/mrpeach { };
  #
  #  mrxvt = callPackage ../applications/misc/mrxvt { };
  
negative.code: #    gtk = gtk3;
  #  };
  #
    bluejeans = callPackage ../applications/networking/browsers/mozilla-plugins/bluejeans { };
  #
  #  bomi = qt5.callPackage ../applications/video/bomi {
  #    youtube-dl = pythonPackages.youtube-dl;
  