[logback-user] how to get all configured appenders over api

[ralph]

hello

I need for a dynamic configuration of a logger, the list of all 
configured appenders (e.g all FileAppender)
even if some appenders are initially not attached to any loggers

ch.qos.logback.classic.Logger log = (ch.qos.logback.classic.Logger) 
LoggerFactory.getLogger("de.foo" );
log.setLevel( Level.DEBUG );
log.setAdditive( false );
log.addAppender( ????? )

how can I get this list of appenders over the logback api?

Regards
Ralph