@Nullable
    default Integer defaultHttp1MaxHeaderSize() {
        return null;
    }
Returns the default maximum length of all HTTP/1 headers in a request or response.
Note that this flag has no effect if a user specified the value explicitly via
{@link ServerBuilder#http1MaxHeaderSize(int)} or
{@link ClientFactoryBuilder#http1MaxHeaderSize(int)}.

<p>This default value of this flag is {@value DefaultFlagsProvider#DEFAULT_HTTP1_MAX_HEADER_SIZE}.
Specify the {@code -Dcom.linecorp.armeria.defaultHttp1MaxHeaderSize=<integer>} JVM option
to override the default value.
core/src/main/java/com/linecorp/armeria/common/FlagsProvider.java