TrackId in FullTrack can be null

[aome510]

Describe the bug
According the specs defined in docs.rs, TrackId in FullTrack is not null. However, get playlist items can return a track object will null id.

To Reproduce
Steps to reproduce the behavior:

1. To get the playlist having a track with null ID, run

curl -X "GET" \
"https://api.spotify.com/v1/playlists/2RI4NLi6npcHfCNQQxP3nM/tracks?limit=100&offset=900" \
-H "Accept: application/json" -H "Content-Type: application/json" \
-H "Authorization: Bearer <TOKEN>" \
> /tmp/data.txt

2. Then run jq .items[].track.id /tmp/data.txt to view the list of track's ids

Expected behavior
There should be at least one null entry

[marioortizmanero]

Oh nice, the docs have been updated and look a bit more detailed now. Which means that the links are broken... I've opened #281 for that.

I was able to reproduce your issue with your indications, which should be fixed with #282. As far as I can tell this happens with local tracks only.

Thanks for the report!