public long maxAge() {
        return maxAge;
    }
Gets the {@code maxAge} setting.

<p>When making a preflight request the client has to perform two requests which can be inefficient.
This setting will set the CORS {@code "Access-Control-Max-Age"} response header and enable the
caching of the preflight response for the specified time. During this time no preflight
request will be made.

@return the time in seconds that a preflight request may be cached.
core/src/main/java/com/linecorp/armeria/server/cors/CorsPolicy.java