block.admin_edit:
  title: 'Configure block'
  route_name: block.admin_edit
  base_route: block.admin_edit

# Per theme block layout pages.
block.admin_display:
  title: 'Block layout'
  route_name: block.admin_display
  base_route: block.admin_display
block.admin_display_theme:
  title: 'Block layout'
  route_name: block.admin_display_theme
  parent_id: block.admin_display
  deriver: 'Drupal\block\Plugin\Derivative\ThemeLocalTask'