# File lib/amq/protocol/frame.rb, line 135
      def decode_payload
        @decoded_payload ||= begin
                               @klass_id, @weight = @payload.unpack(PACK_UINT16_X2)
                               # the total size of the content body, that is, the sum of the body sizes for the
                               # following content body frames. Zero indicates that there are no content body frames.
                               # So this is NOT related to this very header frame!
                               @body_size         = AMQ::Hacks.unpack_64_big_endian(@payload[4..11]).first
                               @data              = @payload[12..-1]
                               @properties        = Basic.decode_properties(@data)
                             end
      end