Question about the SemanticKITTI instance label

[hualuojingye]

thank you very much for your great work. I have a question about SemanticKITTI labels preprocess.

# Load segmentation label
label_file = osp.join(label_dir, '%06d.label'%(sid))
label = np.fromfile(label_file, dtype=np.int32).reshape(-1)
sem_label = label & 0xFFFF  # semantic label in lower half
inst_label = label

in data_prepare/semantickitti/process_semantickitti.py ,why inst_label is the same as the label?