Is it necessary to provide label column in libsvm format txt file?

#1

It seems that the first column of libsvm format txt file is always label. What if I want to predict new samples without label?

https://xgboost.readthedocs.io/en/latest/tutorials/input_format.html

#2

I think I finally figured it out…

https://www.csie.ntu.edu.tw/~cjlin/libsvm/faq.html#f431