which_page_number (PDF::Writer)

          # File lib/pdf/writer.rb, line 2222
    2222:   def which_page_number(page_num, scheme = 0)
    2223:     return nil unless @page_numbering
    2224:
    2225:     num   = nil
    2226:     start = start_num = 1
    2227:
    2228:     @page_numbering[scheme].each do |kk, vv|
    2229:       if kk <= page_num
    2230:         if vv.kind_of?(Hash)
    2231:           unless vv[:starting].nil?
    2232:             start = vv[:starting]
    2233:             start_num = kk
    2234:             num = page_num - start_num + start
    2235:           end
    2236:         else
    2237:           num = nil
    2238:         end
    2239:       end
    2240:     end
    2241:     num
    2242:   end