不是交换channel中的信息吗，怎么这里是交换batch size中的 about open-cd HOT 2 CLOSED

exchange_map = torch.arange(c) % self.p == 0
exchange_mask = exchange_map.unsqueeze(0).expand((N, -1))

import torch

x1  = torch.arange(1, 128+1).reshape(4, 8, 2, 2)
x2  = torch.arange(1, 128+1).reshape(4, 8, 2, 2) * -1
p = 2

N, c, h, w = x1.shape
        
exchange_map = torch.arange(c) % p == 0
exchange_mask = exchange_map.unsqueeze(0).expand((N, -1))

out_x1, out_x2 = torch.zeros_like(x1), torch.zeros_like(x2)
out_x1[~exchange_mask, ...] = x1[~exchange_mask, ...]
out_x2[~exchange_mask, ...] = x2[~exchange_mask, ...]
out_x1[exchange_mask, ...] = x2[exchange_mask, ...]
out_x2[exchange_mask, ...] = x1[exchange_mask, ...]

exchange_mask = exchange_map
out_x11, out_x22 = torch.zeros_like(x1), torch.zeros_like(x2)
out_x11[:, ~exchange_mask, ...] = x1[:, ~exchange_mask, ...]
out_x22[:, ~exchange_mask, ...] = x2[:, ~exchange_mask, ...]
out_x11[:, exchange_mask, ...] = x2[:, exchange_mask, ...]
out_x22[:, exchange_mask, ...] = x1[:, exchange_mask, ...]

print(torch.all(out_x1 == out_x11), torch.all(out_x2 == out_x22))