class_docstr: Given a list of tensors, perform optional spatio-temporal pool and concatenate the
      tensors along the channel dimension.
class_docstr_tok: ["Given","a","list","of","tensors",",","perform","optional","spatio-temporal","pool","and","concatenate","the","tensors","along","the","channel","dimension","."]
docstr: Args:
      retain_list (bool): if True, return the concatenated tensor in a list.
      pool (nn.module_list): if not None, list of pooling models for different
          pathway before performing concatenation.
      dim (int): dimension to performance concatenation.
docstr_tok: ["Args",":","retain_list","(","bool",")",":","if","True",",","return","the","concatenated","tensor","in","a","list",".","pool","(","nn.module_list",")",":","if","not","None",",","list","of","pooling","models","for","different","pathway","before","performing","concatenation",".","dim","(","int",")",":","dimension","to","performance","concatenation","."]
code: def __init__(
      self,
      retain_list: bool = False,
      pool: Optional[nn.ModuleList] = None,
      dim: int = 1,
  ) -> None:
      """
      Args:
          retain_list (bool): if True, return the concatenated tensor in a list.
          pool (nn.module_list): if not None, list of pooling models for different
              pathway before performing concatenation.
          dim (int): dimension to performance concatenation.
      """
      super().__init__()
      set_attributes(self, locals())
  
imports: from typing import Callable, List, Optional, Tuple, Union
  import torch
  import torch.nn
  from pytorchvideo.layers.utils import set_attributes
  from pytorchvideo.models.head import create_res_basic_head, create_res_roi_pooling_head
  from pytorchvideo.models.net import DetectionBBoxNetwork, MultiPathWayWithFuse, Net
  from pytorchvideo.models.resnet import create_bottleneck_block, create_res_stage
  from pytorchvideo.models.stem import create_res_basic_stem
label_desc: Use image node_id 1 to create a new PoolConcatPathway object from inherited base classes: nn with example: obj = PoolConcatPathway(retain_list, pool, dim)