/**
  * Returns the new line item created by adding a purchase of the ticket
  * @param \EE_Line_Item $total_line_item
  * @param EE_Ticket $ticket
  * @param int $qty
  * @return \EE_Line_Item
  * @throws \EE_Error
  */
 public static function increment_ticket_qty_if_already_in_cart(EE_Line_Item $total_line_item, EE_Ticket $ticket, $qty = 1)
 {
     $line_item = null;
     if ($total_line_item instanceof EE_Line_Item && $total_line_item->is_total()) {
         $ticket_line_items = EEH_Line_Item::get_ticket_line_items($total_line_item);
         foreach ((array) $ticket_line_items as $ticket_line_item) {
             if ($ticket_line_item instanceof EE_Line_Item && $ticket_line_item->OBJ_ID() == $ticket->ID()) {
                 $line_item = $ticket_line_item;
                 break;
             }
         }
     }
     if ($line_item instanceof EE_Line_Item) {
         EEH_Line_Item::increment_quantity($line_item, $qty);
         return $line_item;
     }
     return null;
 }