Element link

link =>

array:6 [
  "class" => "Drupal\Core\Render\Element\Link"
  "provider" => "core"
  "id" => "link"
  "#pre_render" => array:1 [
    0 => array:2 [
      0 => "Drupal\Core\Render\Element\Link"
      1 => "preRenderLink"
    ]
  ]
  "#type" => "link"
  "#defaults_loaded" => true
]