public function getCMSFields()
{
$fields = parent::getCMSFields();
$fields->removeFieldFromTab('Root', 'Codes');
$fields->removeFieldFromTab('Root', 'Groups');
$fields->addFieldToTab('Root.Main', $permissionField = new PermissionCheckboxSetField('Codes', Permission::singleton()->i18n_plural_name(), 'SilverStripe\\Security\\PermissionRoleCode', 'RoleID'));
$permissionField->setHiddenPermissions(Permission::config()->hidden_permissions);
return $fields;
}
