code: def build_action_encoder(self):
      if isinstance(self.action_space, Discrete):
          return nn.Embedding(self.action_dim, self.embed_dim)
      elif isinstance(self.action_space, Box):
          return nn.Linear(self.action_dim, self.embed_dim)
      else:
          raise NotImplementedError
  
imports: from typing import Dict, List
  import gymnasium
  import numpy
  from gymnasium.spaces import Box, Discrete
  from ray.rllib import SampleBatch
  from ray.rllib.models import ModelV2
  from ray.rllib.models.torch.mingpt import GPT, GPTConfig
  from ray.rllib.models.torch.torch_modelv2 import TorchModelV2
  from ray.rllib.policy.view_requirement import ViewRequirement
  from ray.rllib.utils import override
  from ray.rllib.utils.framework import try_import_torch
  from ray.rllib.utils.typing import ModelConfigDict, TensorType
label_desc: Use image node_id 4 for calling the DTTorchModel obj's underlying member method code with example usage: obj.build_action_encoder() and returns: nn, nn