public static void addAppender(RollOverAppenderSettings appender) {
    LoggerContext loggerContext = (LoggerContext) LoggerFactory.getILoggerFactory();
    loggerContext .putObject(CoreConstants.FA_FILENAME_COLLISION_MAP, null);
    loggerContext .putObject(CoreConstants.RFA_FILENAME_PATTERN_COLLISION_MAP, null);

    File logFile = appender.getLogFile();
    etc..