Bit-wise NOT operation "~" for padding_mask in data.

[Lionel-Lee]

Hi Zikang,

I noticed you used the bit-wise NOT operation "~" in the argoverse v1 dataset to process padding_mask. You set padding_mask to True or False and use "~padding_mask" to calculate the opposite. However, from my understanding, "~" is used for bit-wise NOT, which means ~True=-2 and ~False=-1, both ~True and ~False are True because they are not 0. I'm kind of confused by this, and I guess you meant to use not padding_mask or 1-padding_mask. Could you please clarify it? Thanks!