text: window.addEventListener('load', (event) => {
      let test = new LocalStorageTest();
      show(test, 'Keys');
  
      test.set('key-1', new Date());
      show(test, 'set() 1');
  
      test.clear();
      show(test, 'clear()');
  
      test.set('key-2', new Date());
      show(test, 'set() 2');
  
      test.remove('key-2');
      show(test, 'remove() 2');
  
      test.set('key-3', new Date());
      show(test, 'set() 3');
  
      function show(c, msg) {
          console.log(`----- ${msg}`);
          for (let key of c.Keys) {
              console.log(`${key}=${c.get(key)}`);
          }
      }
  });
  