docstr: Test that the ViewRequirementAgentConnector can handle slice shifts.
docstr_tok: ["Test","that","the","ViewRequirementAgentConnector","can","handle","slice","shifts","."]
code: def test_vr_connector_causal_slice(self):
      """Test that the ViewRequirementAgentConnector can handle slice shifts."""
      view_rq_dict = {
          "state": ViewRequirement("obs"),
          # shift array should be [-2, -1, 0]
          "prev_states": ViewRequirement("obs", shift="-2:0"),
          # shift array should be [-4, -2, 0]
          "prev_strided_states_even": ViewRequirement(
              "obs", shift="-4:0:2"
          ),
          # shift array should be [-3, -1]
          "prev_strided_states_odd": ViewRequirement(
              "obs", shift="-3:0:2"
          ),
      }
  
      obs_arrs = np.arange(10)[:, None] + 1
      config = PPOConfig().to_dict()
      ctx = ConnectorContext(
          view_requirements=view_rq_dict,
          config=config,
          is_policy_recurrent=True,
      )
      c = ViewRequirementAgentConnector(ctx)
  
      # keep a queue of observations
      obs_list = []
      for t, obs in enumerate(obs_arrs):
          # t=0 is the next state of t=-1
          data = AgentConnectorDataType(
              0, 1, {SampleBatch.NEXT_OBS: obs}
          )
          processed = c([data])
          sample_batch = processed[0].data.sample_batch
  
          if t == 0:
              obs_list.extend([obs for _ in range(5)])
          else:
              # remove the first obs and add the current obs to the end
              obs_list.pop(0)
              obs_list.append(obs)
  
          # check state
          check(sample_batch["state"], obs[None])
  
          # check prev_states
          check(
              sample_batch["prev_states"],
              np.stack(obs_list)[np.array([-3, -2, -1])][None],
          )
  
          # check prev_strided_states_even
          check(
              sample_batch["prev_strided_states_even"],
              np.stack(obs_list)[np.array([-5, -3, -1])][None],
          )
  
          check(
              sample_batch["prev_strided_states_odd"],
              np.stack(obs_list)[np.array([-4, -2])][None],
          )
  
imports: import gymnasium
  from gymnasium.spaces import Box
  import numpy
  import tree
  import unittest
  from ray.rllib.algorithms.ppo.ppo import PPOConfig
  from ray.rllib.connectors.agent.clip_reward import ClipRewardAgentConnector
  from ray.rllib.connectors.agent.lambdas import FlattenDataAgentConnector
  from ray.rllib.connectors.agent.obs_preproc import ObsPreprocessorConnector
  from ray.rllib.connectors.agent.pipeline import AgentConnectorPipeline
  from ray.rllib.connectors.agent.state_buffer import StateBufferConnector
  from ray.rllib.connectors.agent.view_requirement import ViewRequirementAgentConnector
  from ray.rllib.connectors.connector import ConnectorContext
  from ray.rllib.connectors.registry import get_connector
  from ray.rllib.policy.view_requirement import ViewRequirement
  from ray.rllib.policy.sample_batch import SampleBatch
  from ray.rllib.utils.test_utils import check
  from ray.rllib.utils.typing import ActionConnectorDataType, AgentConnectorDataType, AgentConnectorsOutput
  from ray.rllib.connectors.agent.mean_std_filter import MeanStdObservationFilterAgentConnector
label_desc: Use image node_id 3 for calling the TestViewRequirementAgentConnector obj's underlying member method code with example usage: obj.test_vr_connector_causal_slice() without return types