anchor.diff:  
         advisoryDelete = mkOption {
           description = ''
  -	        If set, then require administrative RPC call "can_delete"
  -	        to enable online deletion of ledger records.
  +          If set, then require administrative RPC call "can_delete"
  +          to enable online deletion of ledger records.
           '';
           type = types.nullOr types.bool;
           default = null;
  
positive.code:   portOptions = { name, ...}: {
      options = {
        name = mkOption {
  	internal = true;
  	default = name;
        };
  
        ip = mkOption {
  	default = "127.0.0.1";
  	description = "Ip where rippled listens.";
  	type = types.str;
        };
  
        port = mkOption {
  	description = "Port where rippled listens.";
  	type = types.int;
        };
  
        protocol = mkOption {
  	description = "Protocols expose by rippled.";
  	type = types.listOf (types.enum ["http" "https" "ws" "wss" "peer"]);
        };
  
        user = mkOption {
  	description = "When set, these credentials will be required on HTTP/S requests.";
  	type = types.str;
  	default = "";
        };
  
        password = mkOption {
  	description = "When set, these credentials will be required on HTTP/S requests.";
  	type = types.str;
  	default = "";
        };
  
        admin = mkOption {
  	description = "A comma-separated list of admin IP addresses.";
  	type = types.listOf types.str;
  	default = ["127.0.0.1"];
        };
  
        ssl = {
  	key = mkOption {
  	  description = ''
  	    Specifies the filename holding the SSL key in PEM format.
  	  '';
  	  default = null;
  	  type = types.nullOr types.path;
  	};
  
  	cert = mkOption {
  	  description = ''
  	    Specifies the path to the SSL certificate file in PEM format.
  	    This is not needed if the chain includes it.
  	  '';
  	  default = null;
  	  type = types.nullOr types.path;
  	};
  
  	chain = mkOption {
  	  description = ''
  	    If you need a certificate chain, specify the path to the
  	    certificate chain here. The chain may include the end certificate.
  	  '';
  	  default = null;
  	  type = types.nullOr types.path;
  	};
        };
      };
    };
  
negative.code:       serviceConfig = {
          ExecStart = "${cfg.package}/bin/rippled --fg --conf ${cfg.config}";
          User = "rippled";
          Restart = "on-failure";
          LimitNOFILE=10000;
        };
      };
  
  