public function add_ticket_to_cart( $ticket_id, $quantity, array $extra_data = [], $additive = true ) {
		/** @var WooCommerce $woocommerce */
		global $woocommerce;

		if ( 0 < $quantity ) {
			/**
			 * Allow hooking into WooCommerce Add to Cart validation.
			 *
			 * Note: This is a WooCommerce filter that is not abstracted for API usage so we have to run it manually.
			 *
			 * @param bool $passed_validation Whether the item can be added to the cart.
			 * @param int  $ticket_id         Ticket ID.
			 * @param int  $quantity          Ticket quantity.
			 */
			$passed_validation = apply_filters( 'woocommerce_add_to_cart_validation', true, $ticket_id, $quantity );

			if ( ! $passed_validation ) {
				return;
			}
		}

		try {
			if ( ! $additive ) {
				$cart_item_keys = $this->get_cart_item_keys_for_ticket_in_cart( $ticket_id );

				if ( ! empty( $cart_item_keys ) ) {
					// Remove cart items.
					array_map( [ $woocommerce->cart, 'remove_cart_item' ], $cart_item_keys );
				}
			}

			// Set quantity in cart.
			if ( 0 < $quantity ) {
				$woocommerce->cart->add_to_cart( $ticket_id, $quantity, 0, [], $extra_data );
			}
		} catch ( \Exception $exception ) {
			// Item not added to / removed from cart.
		}
	}