# File lib/rbot/dbhash.rb, line 139
    def DBTree.cleanup_logs()
      begin
        debug "DBTree: checkpointing ..."
        @@env.checkpoint
      rescue Exception => e
        debug "Failed: #{e.pretty_inspect}"
      end
      begin
        debug "DBTree: flushing log ..."
        @@env.log_flush
        logs = @@env.log_archive(BDB::ARCH_ABS)
        debug "DBTree: deleting archivable logs: #{logs.join(', ')}."
        logs.each { |log|
          File.delete(log)
        }
      rescue Exception => e
        debug "Failed: #{e.pretty_inspect}"
      end
    end