ires a valid nonce.', 'woocommerce' ), 401 );
		}

		$valid_nonce = wp_verify_nonce( $nonce, 'wc_store_api' );

		if ( ! $valid_nonce ) {
			throw new RouteException( 'woocommerce_rest_invalid_nonce', __( 'X-WC-Store-API-Nonce is invalid.', 'woocommerce' ), 403 );
		}
	}

	/**
	 * Get route response when something went wrong.
	 *
	 * @param string $error_code String based error code.
	 * @param string $error_message User facing error message.
	 * @param int    $http_status_code HTTP status. Defaults to 500.
	 * @param array  $additional_data  Extra data (key value pairs) to expose in the error response.
	 * @return \WP_Error WP Error object.
	 */
	protected function get_route_error_response( $error_code, $error_message, $http_status_code = 500, $additional_data = [] ) {
		switch ( $http_status_code ) {
			case 409:
				// If there was a conflict, return the cart so the client can resolve it.
				$cart = $this->cart_controller->get_cart_instance();

				return new \WP_Error(
					$error_code,
					$error_message,
					array_merge(
						$additional_data,
						[
							'status' => $http_status_code,
							'cart'   => $this->cart_schema->get_item_response( $cart ),
						]
					)
				);
		}
		return new \WP_Error( $error_code, $error_message, [ 'status' => $http_status_code ] );
	}
}