class_docstr: Simple bias appending layer for free_log_std.
class_docstr_tok: ["Simple","bias","appending","layer","for","free_log_std","."]
code: def forward(self, x: TensorType) -> TensorType:
      out = torch.cat(
          [x, self.log_std.unsqueeze(0).repeat([len(x), 1])], axis=1
      )
      return out
  
imports: import numpy
  from typing import Union, Tuple, Any, List
  from ray.rllib.models.utils import get_activation_fn
  from ray.rllib.utils.annotations import DeveloperAPI
  from ray.rllib.utils.framework import try_import_torch
  from ray.rllib.utils.typing import TensorType
label_desc: Use image node_id 2 for calling the AppendBiasLayer obj's underlying member method code with example usage: obj.forward(x) and returns: out