docstr: Appends the given item to the end of this buffer.
docstr_tok: ["Appends","the","given","item","to","the","end","of","this","buffer","."]
code: def append(self, item) -> None:
      """Appends the given item to the end of this buffer."""
      if self.finalized:
          self.data = tree.map_structure(
              lambda d, i: np.concatenate([d, [i]], axis=0),
              self.data,
              item,
          )
      else:
          self.data.append(item)
  
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 2 for calling the BufferWithInfiniteLookback obj's underlying member method code with example usage: obj.append(item) without return types