reopen

# File lib/logger.rb, line 715
    def reopen(log = nil)
      # reopen the same filename if no argument, do nothing for IO
      log ||= @filename if @filename
      if log
        synchronize do
          if @filename and @dev
            @dev.close rescue nil # close only file opened by Logger
            @filename = nil
          end
          set_dev(log)
        end
      end
      self
    end