docs: async def _send_rtcp_nack(self, media_ssrc, lost):
          """
          Send an RTCP packet to report missing RTP packets.
          """
          if self.__rtcp_ssrc is not None:
              packet = RtcpRtpfbPacket(
                  fmt=RTCP_RTPFB_NACK, ssrc=self.__rtcp_ssrc, media_ssrc=media_ssrc)
              packet.lost = lost
              await self._send_rtcp(packet)