Issue #3106654 by kiamlaluno: hook_toolbar() documentation still makes...

 *   - '#weight': Optional. Integer weight used for sorting toolbar items in

 *     administration bar area.

 *

 * This hook is invoked in toolbar_pre_render().

 * This hook is invoked in Toolbar::preRenderToolbar().

 *

 * @return

 *   An array of toolbar items, keyed by unique identifiers such as 'home' or

 *   'administration', or the short name of the module implementing the hook.

 *   The corresponding value is a render element of type 'toolbar_item'.

 *

 * @see toolbar_pre_render()

 * @see \Drupal\toolbar\Element\Toolbar::preRenderToolbar()

 * @ingroup toolbar_tabs

 */

function hook_toolbar() {