code: function makeStorageHelper(storage) {
    return {
      storage: storage,
      set: function set(name, value, minutes) {
        if (value == null) {
          this.storage.removeItem(name);
        } else {
          this.storage.setItem(name, JSON.stringify({
            value: value,
            expired_at: minutes ? new Date().getTime() + minutes * 60 * 1000 : null
          }));
        }
      },
      get: function get$$1(name) {
        var t = this.storage.getItem(name);
  
        if (t) {
          t = JSON.parse(t);
  
          if (!t.expired_at || t.expired_at > new Date().getTime()) {
            return t.value;
          } else {
            this.storage.removeItem(name);
          }
        }
  
        return null;
      },
      clear: function clear() {
        this.storage.clear();
      }
    };
  }
docs: set null can remove a item