code: function updateBoolean(name) {
    name = ' ' + name;
    function update(value) {
      switch (value) {
        case true:
        case 'true':
          return name;
      }
      return '';
    }
    update[UID] = true;
    return update;
  }
docs: return the right callback to update a boolean attribute after modifying the template to ignore such attribute if falsy