anchor.diff:      checkInterval = mkOption {
         type = types.int;
         default = 0;
  -      example = literalExample "with lib; (length (attrNames config.services.gitlab-runner.services)) * 3";
  +      example = literalExpression "with lib; (length (attrNames config.services.gitlab-runner.services)) * 3";
         description = ''
           Defines the interval length, in seconds, between new jobs check.
           The default value is 3;
  
positive.code:     services = mkOption {
        description = "GitLab Runner services.";
        default = { };
        example = literalExample ''
          {
            # runner for building in docker via host's nix-daemon
            # nix store will be readable in runner, might be insecure
  
negative.code:     concurrent = mkOption {
        type = types.int;
        default = 1;
        example = literalExpression "config.nix.maxJobs";
        description = ''
          Limits how many jobs globally can be run concurrently.
          The most upper limit of jobs using all defined runners.
  