field_menu-8.x-1.0-alpha4/config/schema/field_menu.schema.yml

field_menu.settings:
  type: mapping
  label: 'Field Menu settings'
  mapping:
    menu_type_checkbox:
      type: sequence
      label: 'Available menus'
      sequence:
       type: string
    menu_type_checkbox_negate:
      type: string
      label: 'Negate the condition'