Element language_select

language_select =>

array:13 [
  "class" => "Drupal\Core\Render\Element\LanguageSelect"
  "provider" => "core"
  "id" => "language_select"
  "#input" => true
  "#default_value" => "und"
  "#value_callback" => array:2 [
    0 => "Drupal\Core\Render\Element\LanguageSelect"
    1 => "valueCallback"
  ]
  "#type" => "language_select"
  "#process" => array:3 [
    0 => "language_process_language_select"
    1 => array:2 [
      0 => "Drupal\Core\Render\Element\Select"
      1 => "processSelect"
    ]
    2 => array:2 [
      0 => "Drupal\Core\Render\Element\RenderElementBase"
      1 => "processAjaxForm"
    ]
  ]
  "#theme_wrappers" => array:1 [
    0 => "form_element"
  ]
  "#theme" => "select"
  "#languages" => 1
  "#multiple" => false
  "#defaults_loaded" => true
]