# File lib/innodb/page/sys_rseg_header.rb, line 43
  def each_undo_segment
    unless block_given?
      return enum_for(:each_undo_segment)
    end

    cursor(pos_undo_segment_array).name("undo_segment_array") do |c|
      (0...UNDO_SEGMENT_SLOTS).each do |slot|
        page_number = c.name("slot[#{slot}]") {
          Innodb::Page.maybe_undefined(c.get_uint32)
        }
        yield slot, page_number
      end
    end
  end