LocalTaskManager::$defaults

protected $defaults = array(
  // (required) The name of the route this task links to.
  'route_name' => '',
  // Parameters for route variables when generating a link.
  'route_parameters' => array(),
  // The static title for the local task.
  'title' => '',
  // The route name where the root tab appears.
  'base_route' => '',
  // The plugin ID of the parent tab (or NULL for the top-level tab).
  'parent_id' => NULL,
  // The weight of the tab.
  'weight' => NULL,
  // The default link options.
  'options' => array(),
  // Default class for local task implementations.
  'class' => 'Drupal\Core\Menu\LocalTaskDefault',
  // The plugin id. Set by the plugin system based on the top-level YAML key.
  'id' => '',
);