# File lib/innodb/history_list.rb, line 14
    def initialize(history, undo_record, direction=:forward)
      @history = history
      @undo_record = undo_record

      case undo_record
      when :min
        @undo_log_cursor = history.list.list_cursor(:min, direction)
        if @undo_log = @undo_log_cursor.node
          @undo_record_cursor = @undo_log.undo_record_cursor(:min, direction)
        end
      when :max
        @undo_log_cursor = history.list.list_cursor(:max, direction)
        if @undo_log = @undo_log_cursor.node
          @undo_record_cursor = @undo_log.undo_record_cursor(:max, direction)
        end
      else
        raise "Not implemented"
      end
    end