what's the shape of the padding mask?

[cswwp]

Thanks for sharing so great repo, and one question: what's the shape of the padding mask? and how i construct my padding mask with custom dataset? such as now my padding mask is
[ [1,1,1,1,0,0,0],
[1,1,0,0,0,0,0],
[1,1,1,1,1,1,0],
[1,1,1,1,1,1,1]
]
but i give to encoder.forward, it shows runtime errror, anyone can help me?
@SamLynnEvans