code: def _get_int_index(
      self,
      idx: int,
      fill=None,
      neg_indices_left_of_zero=False,
      one_hot_discrete=False,
  ):
      # If index >= 0 -> Ignore lookback buffer.
      # Otherwise, include lookback buffer.
      if idx >= 0 or neg_indices_left_of_zero:
          idx = self.lookback + idx
      # Negative indices mean: Go to left into lookback buffer starting from idx=0.
      # But if we pass the lookback buffer, the index should be invalid and we will
      # have to fill, if required. Invalidate the index by setting it to one larger
      # than max.
      if neg_indices_left_of_zero and idx < 0:
          idx = len(self) + self.lookback
  
      try:
          if self.finalized:
              data = tree.map_structure(lambda s: s[idx], self.data)
          else:
              data = self.data[idx]
      # Out of range index -> If `fill`, use a fill dummy (B=0), if not, error out.
      except IndexError as e:
          if fill is not None:
              return get_dummy_batch_for_space(
                  self.space,
                  fill_value=fill,
                  batch_size=0,
                  one_hot_discrete=one_hot_discrete,
              )
          else:
              raise e
  
      # Convert discrete/multi-discrete components to one-hot vectors, if required.
      if one_hot_discrete:
          data = self._one_hot(data, self.space_struct)
      return data
  
imports: import logging
  from typing import List, Optional, Type, Union
  import gymnasium
  import numpy
  import tree
  from ray.rllib.env.env_context import EnvContext
  from ray.rllib.env.multi_agent_env import MultiAgentEnv
  from ray.rllib.env.wrappers.multi_agent_env_compatibility import MultiAgentEnvCompatibility
  from ray.rllib.utils.error import ERR_MSG_INVALID_ENV_DESCRIPTOR, ERR_MSG_OLD_GYM_API, EnvError
  from ray.rllib.utils.gym import check_old_gym_env
  from ray.rllib.utils.numpy import one_hot, one_hot_multidiscrete
  from ray.rllib.utils.spaces.space_utils import batch, get_dummy_batch_for_space, get_base_struct_from_space
  from ray.util import log_once
  from ray.util.annotations import PublicAPI
label_desc: Use image node_id 16 for calling the BufferWithInfiniteLookback obj's underlying member method code with example usage: obj._get_int_index(idx, fill, neg_indices_left_of_zero, one_hot_discrete) and returns: data, get_dummy_batch_for_space