Wizard Advanced Help Error

Been going through the Advanced Help examples for building a multistep form wizard and I noticed there was an error in the example function delegator_page_add_subtask_next(&$form_state). I've attached a small patch to correct the issue. But for those searching, below is the correct example.

/**
 * Callback generated when the 'next' button is clicked.
 *
 * All we do here is store the cache.
 */
function delegator_page_add_subtask_next(&$form_state) {
  // Update the cache with changes.
  delegator_page_set_page_cache($form_state['cache name'], $form_state['page']);
}