question: protected void cleanUp ( ) { if ( isReleaseReferences ( ) ) { cleanUpOnAck ( ) ; if ( logger . isLoggingEnabled ( LogWriter . TRACE_DEBUG ) ) { logger . logDebug ( "dialog cleanup : " + getDialogId ( ) ) ; } if ( eventListeners != null ) { eventListeners . clear ( ) ; } timerTaskLock = null ; ackSem = null ; contactHeader = null ; eventHeader = null ; firstTransactionId = null ; firstTransactionMethod = null ; lastResponseDialogId = null ; lastResponseMethod = null ; lastResponseTopMostVia = null ; if ( originalRequestRecordRouteHeaders != null ) { originalRequestRecordRouteHeaders . clear ( ) ; originalRequestRecordRouteHeaders = null ; originalRequestRecordRouteHeadersString = null ; } if ( routeList != null ) { routeList . clear ( ) ; routeList = null ; } responsesReceivedInForkingCase . clear ( ) ; } }
target:  Release references so the GC can clean up dialog state.