anchor.diff:        ''
           Protocol 2
   
  -        UsePAM yes
  +        UsePAM ${if cfg.usePAM then "yes" else "no"}
   
           ${concatMapStrings (port: ''
             Port ${toString port}
  
positive.code:           Specifies on which ports the SSH daemon listens.
          '';
        };
        
        extraConfig = mkOption {
          default = "";
          description = "Verbatim contents of <filename>sshd_config</filename>.";
  
negative.code: 
          PermitRootLogin ${cfg.permitRootLogin}
          GatewayPorts ${cfg.gatewayPorts}
          PasswordAuthentication ${if cfg.passwordAuthentication then "yes" else "no"}
        '';
  
    };
  