class_docstr: A simple FC model that takes the last n observations as input.
class_docstr_tok: ["A","simple","FC","model","that","takes","the","last","n","observations","as","input","."]
code: def value_function(self):
      return torch.squeeze(self._last_value, -1)
  
file_path: ray/python/ray/rllib/examples/models/trajectory_view_utilizing_models.py
imports: from ray.rllib.models.tf.tf_modelv2 import TFModelV2
  from ray.rllib.models.torch.misc import SlimFC
  from ray.rllib.models.torch.torch_modelv2 import TorchModelV2
  from ray.rllib.policy.view_requirement import ViewRequirement
  from ray.rllib.utils.framework import try_import_tf, try_import_torch
  from ray.rllib.utils.tf_utils import one_hot
  from ray.rllib.utils.torch_utils import one_hot
label_desc: Use image node_id 3 for calling the TorchFrameStackingCartPoleModel obj's underlying member method code with example usage: obj.value_function() and returns: torch