/**
  * When an invoice was paid we need to notify taxamo of the transaction.
  *
  * @since  1.0.0
  * @param  MS_Model_Invoice $invoice The processed invoice.
  */
 public function invoice_paid($invoice)
 {
     if (!$invoice->is_paid()) {
         return;
     }
     if (0 == $invoice->total) {
         return;
     }
     $membership = $invoice->get_membership();
     $member = $invoice->get_member();
     MS_Addon_Taxamo_Api::register_payment($invoice->total, $membership->name, $invoice->tax_rate, $invoice->get_invoice_number(), $member->full_name, $member->email, $invoice->gateway_id, $invoice->currency, $invoice->checkout_ip);
 }