@SuppressWarnings("unchecked")
    private boolean isSocketAppender(Appender<ILoggingEvent> appender) {
        if (appender instanceof AbstractSocketAppender) {
            return true;
        }
        if (appender instanceof AppenderAttachable) {
            for (final Iterator<Appender<ILoggingEvent>> i = ((AppenderAttachable<ILoggingEvent>) appender)
                    .iteratorForAppenders(); i.hasNext();) {
                if (isSocketAppender(i.next())) {
                    return true;
                }
            }
        }
        return false;
    }
Stores the specified {@link RequestContextExporterBuilder} customizer to be lazily applied when
the exporter is built.
logback/logback12/src/main/java/com/linecorp/armeria/common/logback/RequestContextExportingAppender.java