Element toolbar

toolbar =>

array:10 [
  "class" => "Drupal\toolbar\Element\Toolbar"
  "provider" => "toolbar"
  "id" => "toolbar"
  "#pre_render" => array:1 [
    0 => array:2 [
      0 => "Drupal\toolbar\Element\Toolbar"
      1 => "preRenderToolbar"
    ]
  ]
  "#theme" => "toolbar"
  "#attached" => array:1 [
    "library" => array:1 [
      0 => "toolbar/toolbar"
    ]
  ]
  "#attributes" => array:3 [
    "id" => "toolbar-administration"
    "role" => "group"
    "aria-label" => Drupal\Core\StringTranslation\TranslatableMarkup {#1638
      #string: "Site administration toolbar"
      #arguments: []
      #translatedMarkup: null
      #options: []
      #stringTranslation: null
    }
  ]
  "#bar" => array:2 [
    "#heading" => Drupal\Core\StringTranslation\TranslatableMarkup {#1639
      #string: "Toolbar items"
      #arguments: []
      #translatedMarkup: null
      #options: []
      #stringTranslation: null
    }
    "#attributes" => array:3 [
      "id" => "toolbar-bar"
      "role" => "navigation"
      "aria-label" => Drupal\Core\StringTranslation\TranslatableMarkup {#1640
        #string: "Toolbar items"
        #arguments: []
        #translatedMarkup: null
        #options: []
        #stringTranslation: null
      }
    ]
  ]
  "#type" => "toolbar"
  "#defaults_loaded" => true
]