# File lib/pdf/reader/reference.rb, line 33
    def self.from_buffer (buffer)
      buffer.ready_token
      return nil unless m = buffer.raw.match(/^(\d+)\s+(\d+)\s+R\b/)
      buffer.head(m[0].size)
      self.new(m[1].to_i, m[2].to_i)
    end