code: def forward(self, x1, x2):
      fusion = torch.cat([x1, x2], dim=1)
      out = self.conv1x1(fusion)
      attention = self.channel_attention(out)
      out = out + out * attention
      return out
  
imports: import torch
  import torch.nn
  import torch.nn.functional
  from pywick.models.segmentation.da_basenets.resnet import resnet18
label_desc: Use image node_id 2 for calling the FeatureFusion obj's underlying member method code with example usage: obj.forward(x1, x2) and returns: out