先利用卷积神经网络（CNN）把图片输入，然后使用注意力机制来关注图片中的某一特定区域，并有选择性地把所关注的信息扩散到全局。给出上述pytorch代码

这可以通过使用PyTorch的nn.Conv2d和nn.Attention模块来实现。例如：import torch.nn as nn # Construct the Conv2d layer conv2d_layer = nn.Conv2d(in_channels=1, out_channels=16, kernel_size=(3, 3), padding=1) # Construct the Attention layer attention_layer = nn.Attention(attention_type='global') # Pass the input image through the Conv2d layer output = conv2d_layer(input_image) # Pass the output of the Conv2d layer to the Attention layer attention_output = attention_layer(output)