docstr: human readable representation of the DTensorSpec
docstr_tok: ["human","readable","representation","of","the","DTensorSpec"]
code: def __str__(self) -> str:
      """
      human readable representation of the DTensorSpec
      """
      if len(self.placements) == 1:
          placement_str = str(self.placements[0])
      else:
          placement_str = str(self.placements)
  
      if self.tensor_meta is not None:
          tensor_shape = str(tuple(self.tensor_meta.shape))
      else:
          tensor_shape = "unknown shape"
  
      return f"Spec({placement_str} on {tensor_shape})"
  
imports: from dataclasses import dataclass
  from typing import Any, cast, List, NamedTuple, Optional, Tuple
  import torch
  import torch.distributed._functional_collectives
  import torch.distributed.distributed_c10d
  from torch.distributed._tensor._collective_utils import mesh_broadcast, mesh_scatter
  from torch.distributed.device_mesh import DeviceMesh
label_desc: Use image node_id 6 for calling the DTensorSpec obj's underlying member method code with example usage: obj.__str__() and returns: str, placement_str, str, tensor_shape, str