parse_range_header

# File lib/webrick/httputils.rb, line 181
    def parse_range_header(ranges_specifier)
      if /^bytes=(.*)/ =~ ranges_specifier
        byte_range_set = split_header_value($1)
        byte_range_set.collect{|range_spec|
          case range_spec
          when /^(\d+)-(\d+)/ then $1.to_i .. $2.to_i
          when /^(\d+)-/      then $1.to_i .. -1
          when /^-(\d+)/      then -($1.to_i) .. -1
          else return nil
          end
        }
      end
    end