[logback-dev] how to get appender-ref list via Joran

I am trying to develop a new appender for Async logging - a non- blocking appender similar to http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/AsyncAppender.h... Config is like: <appender name="async" class="logback.AsyncAppender"> <bufferSize>20</bufferSize> <appender-ref ref="stdout" /> <appender-ref ref="file" /> </appender> Question: How do I get list of appenders (the appender-ref's) in my code? Thanks