Element machine_name

machine_name =>

array:17 [
  "class" => "Drupal\Core\Render\Element\MachineName"
  "provider" => "core"
  "id" => "machine_name"
  "#input" => true
  "#default_value" => null
  "#required" => true
  "#maxlength" => 64
  "#size" => 60
  "#autocomplete_route_name" => false
  "#process" => array:3 [
    0 => array:2 [
      0 => "Drupal\Core\Render\Element\MachineName"
      1 => "processMachineName"
    ]
    1 => array:2 [
      0 => "Drupal\Core\Render\Element\MachineName"
      1 => "processAutocomplete"
    ]
    2 => array:2 [
      0 => "Drupal\Core\Render\Element\MachineName"
      1 => "processAjaxForm"
    ]
  ]
  "#element_validate" => array:1 [
    0 => array:2 [
      0 => "Drupal\Core\Render\Element\MachineName"
      1 => "validateMachineName"
    ]
  ]
  "#pre_render" => array:1 [
    0 => array:2 [
      0 => "Drupal\Core\Render\Element\MachineName"
      1 => "preRenderTextfield"
    ]
  ]
  "#theme" => "input__textfield"
  "#theme_wrappers" => array:1 [
    0 => "form_element"
  ]
  "#value_callback" => array:2 [
    0 => "Drupal\Core\Render\Element\MachineName"
    1 => "valueCallback"
  ]
  "#type" => "machine_name"
  "#defaults_loaded" => true
]