docs: def getSynchronizationSources(self):
          """
          Returns a :class:`RTCRtpSynchronizationSource` for each unique SSRC identifier
          received in the last 10 seconds.
          """
          cutoff = clock.current_datetime() - datetime.timedelta(seconds=10)
          sources = []
          for source, timestamp in self.__active_ssrc.items():
              if timestamp >= cutoff:
                  sources.append(RTCRtpSynchronizationSource(source=source, timestamp=timestamp))
          return sources