@VisibleForTesting
    @Nullable
    String defaultLogName() {
        return defaultLogName;
    }
Sets the default value of the {@link RequestLog#name()} property which is used when no name was set via
{@link RequestLogBuilder#name(String, String)}.

@param defaultLogName the default log name.
core/src/main/java/com/linecorp/armeria/server/VirtualHostBuilder.java