C API: SoundSequence::addTrack() missing parameter?

The addTrack docs say:

"Adds the given playdate.sound.track to the sequence."

The Lua function signature matches the docs, taking a track parameter:


However the C API function returns a SequenceTrack* instead of receiving one. Is this allocating a new SequenceTrack or is it missing its parameter?

SequenceTrack* (*addTrack)(SoundSequence* seq);