Audio trait property in MusicKit

Hi there!

I went through the Apple Music API and stumbled upon Get a Catalog Song's Relationship Directly by Name, an endpoint to fetch a song's relationship by using its identifier.

If you take a look at the example given on the page:

https://api.music.apple.com/v1/catalog/us/songs/1572278914/albums

And see the response, it has a property called audioTraits:

“audioTraits”: [                   
“lossy-stereo”,                    
“lossless”,                    
“atmos”,                    
“spatial”              
]

And another one hasTimeSyncedLyrics:

“hasTimeSyncedLyrics”: true

Although, I cannot find these two properties in MusicKit's Song.

If I hit the API directly using a developer token generated, it does not have these properties as well.

I know Apple cannot disclose if these properties will be available in the future or not, but curious nonetheless.