code: def concat_obs_and_action(obs_and_action):
      """Concat observation and action to feed the critic."""
      assert len(obs_and_action) == 2
      return torch.cat(obs_and_action, dim=-1)
  
imports: import torch
  from pfrl.nn.lmbda import Lambda
label_desc: Use image node_id 1 for calling a global function with example usage: concat_obs_and_action(obs_and_action) and returns: torch