class_docstr: Skip connection used in ResNet3D model.
code: def forward(self, x):
      return self.branch1_bn(self.branch1(x))
  
imports: import torch.nn
  from .r2plus1_util import r2plus1_unit
label_desc: Use image node_id 2 for calling the PostactivatedShortcutTransformation obj's underlying member method code with example usage: obj.forward(x) and returns: self