question about backward_tracking

[XiaoyuShi97]

https://github.com/16lemoing/dot/blob/e32c6f7de12342460371f2efc4789bd79c4a39a3/dot/models/shelf/cotracker2_utils/predictor.py#L145-L153

Hi, I am a bit confused about backward_tracking. First, back_tracking means computing the trajectory starting from the last frame to the first N-1 frames? If so, does backward_tracking benefit (get higher accuracy) from forward_tracking? And do the variables "tracks and visibilities" in L153 overwrite those in L145? Thanks!