Element dropbutton

Add to Standard shortcuts
dropbutton =>
array:7 [
  "class" => "Drupal\Core\Render\Element\Dropbutton"
  "provider" => "core"
  "id" => "dropbutton"
  "#pre_render" => array:1 [
    0 => array:2 [
      0 => "Drupal\Core\Render\Element\Dropbutton"
      1 => "preRenderDropbutton"
    ]
  ]
  "#theme" => "links__dropbutton"
  "#type" => "dropbutton"
  "#defaults_loaded" => true
]