static function get_trigger_types($email_type = '')
 {
     $order_statuses = (array) get_terms('shop_order_status', array('hide_empty' => 0, 'orderby' => 'id'));
     $triggers = self::$triggers;
     $order_triggers = array();
     if (!isset($order_statuses['errors'])) {
         foreach ($order_statuses as $status) {
             $triggers[$status->slug] = sprintf(__('after Order Status: %s', 'wc_followup_emails'), $status->name);
             $order_triggers[] = $status->slug;
             //self::$email_type_triggers['normal'][]  = $status->slug;
             //self::$email_type_triggers['generic'][] = $status->slug;
         }
     }
     self::$email_type_triggers['normal'] = array_unique(array_merge(self::$email_type_triggers['normal'], $order_triggers));
     self::$email_type_triggers['generic'] = array_unique(array_merge(self::$email_type_triggers['generic'], $order_triggers));
     $triggers = apply_filters('fue_trigger_types', $triggers, $email_type);
     self::$triggers = $triggers;
     return self::$triggers;
 }
 static function get_trigger_types()
 {
     $order_statuses = (array) get_terms('shop_order_status', array('hide_empty' => 0, 'orderby' => 'id'));
     $triggers = self::$triggers;
     if (!isset($order_statuses['errors'])) {
         foreach ($order_statuses as $status) {
             $triggers[$status->slug] = sprintf(__('Order Status: %s', 'wc_followup_emails'), $status->name);
         }
     }
     self::$triggers = $triggers;
     return apply_filters('fue_trigger_types', self::$triggers);
 }