def format_holders
      @holders.uniq!
      @holders.sort!
      holders = {}
      logger.debug "Holders are: #{@holders.join(',')}"
      @holders.map { |m| holders[m] = true }
      @holders = holders
    end
def format_holders
      @holders.uniq!
      @holders.sort!
      holders = {}
      logger.debug "Holders are: #{@holders.join(',')}"
      @holders.map { |m| holders[m] = true }
      @holders = holders
    end
Format the list of holders for the lock file