docs: async function tree(dir, files) {
        log.trace.configure({ reading: dir });
  
        const { filter } = conf;
        const ls = await readdir(dir, conf.options);
  
        for (let i = 0; i < ls.length; i += 1) {
          const file = path.join(dir, ls[i]);
          if (!filter || filter([file]).length) {
            log.trace.configure({ passed_fitler: file });
            files.push(file);
  
            // eslint-disable-next-line no-await-in-loop
            if ((await stat(file)).isDirectory()) {
              log.trace.configure({ recursing: file });
              // eslint-disable-next-line no-await-in-loop
              await tree(file, files);
            }
          }
        }
  
        return files;
      }