public Set<HttpMethod> allowedRequestMethods() {
        return allowedRequestMethods;
    }
Returns the allowed set of request methods. The Http methods that should be returned in the
CORS {@code "Access-Control-Request-Method"} response header.

@return the {@link HttpMethod}s that represent the allowed request methods.
core/src/main/java/com/linecorp/armeria/server/cors/CorsPolicy.java