Element managed_file

managed_file =>

array:21 [
  "class" => "Drupal\file\Element\ManagedFile"
  "provider" => "file"
  "id" => "managed_file"
  "#input" => true
  "#process" => array:1 [
    0 => array:2 [
      0 => "Drupal\file\Element\ManagedFile"
      1 => "processManagedFile"
    ]
  ]
  "#element_validate" => array:1 [
    0 => array:2 [
      0 => "Drupal\file\Element\ManagedFile"
      1 => "validateManagedFile"
    ]
  ]
  "#pre_render" => array:2 [
    0 => array:2 [
      0 => "Drupal\file\Element\ManagedFile"
      1 => "preRenderManagedFile"
    ]
    1 => array:2 [
      0 => "Drupal\claro\ClaroPreRender"
      1 => "managedFile"
    ]
  ]
  "#theme" => "file_managed_file"
  "#theme_wrappers" => array:1 [
    0 => "form_element"
  ]
  "#progress_indicator" => "throbber"
  "#progress_message" => null
  "#upload_validators" => []
  "#upload_location" => null
  "#size" => 22
  "#multiple" => false
  "#extended" => false
  "#attached" => array:1 [
    "library" => array:1 [
      0 => "file/drupal.file"
    ]
  ]
  "#accept" => null
  "#value_callback" => array:2 [
    0 => "Drupal\file\Element\ManagedFile"
    1 => "valueCallback"
  ]
  "#type" => "managed_file"
  "#defaults_loaded" => true
]