code: public final boolean roll(final LoggingEvent loggingEvent) {
      for (int i = 0; i < this.fileRollables.length; i++) {
        if (this.fileRollables[i].roll(loggingEvent)) {
          return true;
        }
      }
      return false;
    }
docs: Delegates file rolling to composed objects.
  
  @see FileRollable#roll(org.apache.log4j.spi.LoggingEvent)