anchor.diff:  
           daemonType = "fork";
   
  -        exec = 
  +        exec =
             ''
               ${pkgs.openssh}/sbin/sshd -h /etc/ssh/ssh_host_dsa_key \
                 -f ${pkgs.writeText "sshd_config" cfg.extraConfig}
  
positive.code: {
  
    ###### interface
    
    options = {
    
      services.openssh = {
  
        enable = mkOption {
  
negative.code:         default = "";
          description = "Verbatim contents of <filename>sshd_config</filename>.";
        };
  
      };
  
    };
  