code: private TrackSourceSlot findTrackSourceSlot() {
          TrackSourceSlot result = TRACK_SOURCE_SLOT_MAP.get(packetBytes[41]);
          if (result == null) {
              return TrackSourceSlot.UNKNOWN;
          }
          return result;
      }
docs: Determine the enum value corresponding to the track source slot found in the packet.
  
  @return the proper value