Mean play count of the played tracks; 0 when none was played.
Mean rating of the rated tracks; 0 when none is rated.
Highest play count of any track.
Tracks played at least once.
Tracks with a rating.
Always true here; a failed call resolves with ApiFailure instead.
Sum of all play counts.
Tracks in the media library.
Tracks never played.
Successful response from
playcount.getStats.