anchor.diff:        rsaKey = mkOption {
           default = null;
           example = literalExample "/root/certificates/irc.key";
  +        type = types.nullOr types.path;
           description = "
             IRCD server RSA key.
           ";
  
positive.code: 
        serverName = mkOption {
          default = "hades.arpa";
          description = "
            IRCD server name.
          ";
  
negative.code: 
        adminEmail = mkOption {
          default = "<bit-bucket@example.com>";
          type = types.str;
          example = "<name@domain.tld>";
          description = "
            IRCD server administrator e-mail.
  