We don't have such a method, but you can easily use the get method to do this:

Storage.set('date', new Date());
Storage.set('example', '');

console.log(Boolean(Storage.get('date'))); // -> true
console.log(Boolean(Storage.get('example'))); // -> false
console.log(Boolean(Storage.get('example2'))); // -> false

In some cases, you may want to store false in storage. In this case, it is better to create an additional method that will check it:

Storage.set('false', false);

const has = (name) => {
  const storageValue = Storage.get(name);
  return storageValue === false ? true : Boolean(storageValue);
}

console.log(has('false')); // -> true