public function commerce_get_tickets_in_cart( $tickets ) {
		/** @var Tribe__Tickets__Commerce__PayPal__Gateway $gateway */
		$gateway = tribe( 'tickets.commerce.paypal.gateway' );

		$invoice_number = $gateway->get_invoice_number( false );

		if ( empty( $invoice_number ) ) {
			return $tickets;
		}

		/** @var Tribe__Tickets__Commerce__PayPal__Cart__Interface $cart */
		$cart = tribe( 'tickets.commerce.paypal.cart' );

		$cart->set_id( $invoice_number );

		$contents = $cart->get_items();

		if ( empty( $contents ) ) {
			return $tickets;
		}

		$event_key  = $this->event_key;
		$optout_key = $this->attendee_optout_key;

		foreach ( $contents as $ticket_id => $item ) {
			$optout = false;

			if ( is_array( $item ) ) {
				$ticket_quantity = $item['quantity'];

				if ( isset( $item[ $this->attendee_optout_key ] ) ) {
					$optout = $item[ $this->attendee_optout_key ];
				}
			} else {
				$ticket_quantity = $item;
			}

			$post_id = (int) get_post_meta( $ticket_id, $event_key, true );

			if ( empty( $post_id ) ) {
				continue;
			}

			$optout = filter_var( $optout, FILTER_VALIDATE_BOOLEAN );
			$optout = $optout ? 'yes' : 'no';

			$tickets[] = [
				'ticket_id' => $ticket_id,
				'quantity'  => $ticket_quantity,
				'post_id'   => $post_id,
				'optout'    => $optout,
				'provider'  => 'tribe-commerce',
			];
		}

		return $tickets;
	}