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

可以使用以下代码实现：import torch
import torch.nn as nn#定义卷积神经网络
class CNN(nn.Module):
def __init__(self):
super(CNN, self).__init__()
self.conv1 = nn.Conv2d(3, 32, 3, 1, 1)
self.conv2 = nn.Conv2d(32, 64, 3, 1, 1)
self.conv3 = nn.Conv2d(64, 128, 3, 1, 1)
self.pool1 = nn.MaxPool2d(2)
self.pool2 = nn.MaxPool2d(2)
self.fc1 = nn.Linear(4 * 4 * 128, 128)
self.fc2 = nn.Linear(128, 2)
self.attn = nn.MultiheadAttention(128, 8)

def forward(self, x):
x = self.conv1(x)
x = self.pool1(x)
x = self.conv2(x)
x = self.pool2(x)
x = self.conv3(x)
x = self.pool2(x)
x = x.view(-1, 4 * 4 * 128)
x = self.fc1(x)
x, _ = self.attn(x, x, x)
x = self.fc2(x)
return x