code: @SuppressWarnings("WeakerAccess")
      public TrackMetadata requestMetadataFrom(final CdjStatus status) {
          if (status.getTrackSourceSlot() == CdjStatus.TrackSourceSlot.NO_TRACK || status.getRekordboxId() == 0) {
              return null;
          }
          final DataReference track = new DataReference(status.getTrackSourcePlayer(), status.getTrackSourceSlot(),
                  status.getRekordboxId());
          return requestMetadataFrom(track, status.getTrackType());
      }
docs: Given a status update from a CDJ, find the metadata for the track that it has loaded, if any. If there is
  an appropriate metadata cache, will use that, otherwise makes a query to the players dbserver.
  
  @param status the CDJ status update that will be used to determine the loaded track and ask the appropriate
  player for metadata about it
  
  @return the metadata that was obtained, if any