def pretty_print(q)
      q.text("AbsoluteSet[#{size}/#{@universe.size}]")
      q.group(2, "(", ")") do
        q.breakable ""

        elements = to_a
        elements.take(5).each do |e|
          unless q.current_group.first?
            q.text ","
            q.breakable
          end
          q.pp e
        end

        if elements.length > 5
          q.text ","
          q.breakable
          q.text "..."
        end
      end
    end
def pretty_print(q)
      q.text("AbsoluteSet[#{size}/#{@universe.size}]")
      q.group(2, "(", ")") do
        q.breakable ""

        elements = to_a
        elements.take(5).each do |e|
          unless q.current_group.first?
            q.text ","
            q.breakable
          end
          q.pp e
        end

        if elements.length > 5
          q.text ","
          q.breakable
          q.text "..."
        end
      end
    end
@group Set Ordering

 (see AbstractSet#==)
 @group Pretty Printing

 @return [void]