anchor.diff:          name = "v2ray.json";
           text = builtins.toJSON cfg.config;
           checkPhase = ''
  -          ${pkgs.v2ray}/bin/v2ray -test -config $out
  +          ${cfg.package}/bin/v2ray -test -config $out
           '';
         };
   
  
positive.code:           Whether to run v2ray server.
  
            Either <literal>configFile</literal> or <literal>config</literal> must be specified.
          '';
        };
  
  
negative.code:       description = "v2ray Daemon";
        after = [ "network.target" ];
        wantedBy = [ "multi-user.target" ];
        serviceConfig = {
          ExecStart = "${cfg.package}/bin/v2ray -config ${configFile}";
        };
      };
    };
  }
  