text: const h_cashe = (req, res, cache) => {
      const url = req.url.substring(1);// req.url = /1.txt
      // substring(1) return from index = 1 to end
      if (!url) {
          const keys = cache.keys();
          for (let item of keys) {
              res.write(item + '\n')
          }
          // cache.keys.forEach(item => {
          //     res.write(item + '\n')
          // })
          res.end();
      } else {
          console.log({url, cache});
  
          const data = cache.get(url);
          if (data) res.end(data);
          else res.end('File ' + url + 'not found');
      }
  };
  
  module.exports = h_cashe;