anchor.diff:  
         extraSettings = mkOption {
           default = "";
  +        type = types.lines;
           description = ''
             Will be inserted in the Settings section of the config file.
           '';
  
positive.code: 
        extraDefaults = mkOption {
          default = "";
          description = ''
            Will be inserted in the Default section of the config file.
          '';
  
negative.code: 
        portNumber = mkOption {
          default = 6667;
          type = types.int;
          description = ''
            Number of the port BitlBee will be listening to.
          '';
  