Method finaliseUninstall

/**
 * Method to finalise the uninstallation processing
 *
 * @return  boolean
 *
 * @since   4.0.0
 * @throws  \RuntimeException
 */
protected function finaliseUninstall() : bool
{
    $db = $this->parent->getDbo();
    $query = $db->getQuery(true);
    $element = $this->extension->element;
    $clientId = $this->extension->client_id;
    $extensionId = $this->extension->extension_id;
    // Set menu that assigned to the template back to default template
    $subQuery = $db->getQuery(true)->select($db->quoteName('s.id'))->from($db->quoteName('#__template_styles', 's'))->where([$db->quoteName('s.template') . ' = :element', $db->quoteName('s.client_id') . ' = :clientId']);
    $query->bind(':element', $element)->bind(':clientId', $clientId, ParameterType::INTEGER);
    $query->update($db->quoteName('#__menu'))->set($db->quoteName('template_style_id') . ' = 0')->where($db->quoteName('template_style_id') . ' IN (' . (string) $subQuery . ')');
    $db->setQuery($query);
    $db->execute();
    // Remove the template's styles
    $query = $db->getQuery(true)->delete($db->quoteName('#__template_styles'))->where([$db->quoteName('template') . ' = :template', $db->quoteName('client_id') . ' = :client_id'])->bind(':template', $element)->bind(':client_id', $clientId, ParameterType::INTEGER);
    $db->setQuery($query);
    $db->execute();
    // Remove the schema version
    $query = $db->getQuery(true)->delete($db->quoteName('#__schemas'))->where($db->quoteName('extension_id') . ' = :extension_id')->bind(':extension_id', $extensionId, ParameterType::INTEGER);
    $db->setQuery($query);
    $db->execute();
    // Clobber any possible pending updates
    $update = Table::getInstance('update');
    $uid = $update->find(['element' => $this->extension->element, 'type' => $this->type, 'client_id' => $this->extension->client_id]);
    if ($uid) {
        $update->delete($uid);
    }
    $this->extension->delete();
    return true;
}