code: @SuppressWarnings("WeakerAccess")
      public TrackMetadata requestMetadataFrom(final DataReference track, final CdjStatus.TrackType trackType) {
          return requestMetadataInternal(track, trackType, false);
      }
docs: Ask the specified player for metadata about the track in the specified slot with the specified rekordbox ID,
  unless we have a metadata cache available for the specified media slot, in which case that will be used instead.
  
  @param track uniquely identifies the track whose metadata is desired
  @param trackType identifies the type of track being requested, which affects the type of metadata request
  message that must be used
  
  @return the metadata, if any