Method updateTemplate

/**
 * Update an existing mail template
 *
 * @param   string  $key       Mail template key
 * @param   string  $subject   A default subject (normally a translatable string)
 * @param   string  $body      A default body (normally a translatable string)
 * @param   array   $tags      Associative array of tags to replace
 * @param   string  $htmlbody  A default htmlbody (normally a translatable string)
 *
 * @return  boolean  True on success, false on failure
 *
 * @since   4.0.0
 */
public static function updateTemplate($key, $subject, $body, $tags, $htmlbody = '')
{
    $db = Factory::getDbo();
    $template = new \stdClass();
    $template->template_id = $key;
    $template->language = '';
    $template->subject = $subject;
    $template->body = $body;
    $template->htmlbody = $htmlbody;
    $params = new \stdClass();
    $params->tags = array($tags);
    $template->params = json_encode($params);
    return $db->updateObject('#__mail_templates', $template, ['template_id', 'language']);
}