code: def forward(self, x):
      bs, _, _, _, _ = x.size()
      x = self.conv1_middle(x)
      x = self.bn1_middle(x)
      x = self.relu(x)
  
      x = self.conv1(x)
      x = self.bn1(x)
      x = self.relu(x)
  
      x = self.layer1(x)
      x = self.layer2(x)
      x = self.layer3(x)
      x = self.layer4(x)
  
      x = self.avgpool(x)
      x = x.view(bs, -1)
  
      if self.feat_ext:
          return x
  
      logits = self.out_fc(x)
      return logits
  
file_path: gluon-cv/gluoncv/torch/model_zoo/action_recognition/r2plus1dv2.py
imports: import torch
  import torch.nn
label_desc: Use image node_id 3 for calling the ResNet_R2plus1Dv2 obj's underlying member method code with example usage: obj.forward(x) and returns: logits, x