code: def bias(self) -> Optional[Tensor]:
      return self.linear.bias
  
imports: import torch.nn
  from torch import Tensor
  from typing import Any
  from typing import Dict
  from typing import Type
  from typing import Optional
  from torch.nn import Module
  from cftool.misc import WithRegister
  from .norms import BN
  from .customs import Linear
  from .activations import Activation
label_desc: Use image node_id 3 for calling the Mapping obj's underlying member method code with example usage: obj.bias() and returns: self