code: def _reduce_scatter_tensor_meta(
      input, reduce_op, tag, rankset, group_size
  ):
      out_size = list(input.size())
      out_size[0] //= group_size
      return input.new_empty(out_size)
  
imports: import sys
  import warnings
  from typing import cast, List, Optional, Tuple, TYPE_CHECKING, Union
  import torch
  import torch.distributed
  import torch.distributed.distributed_c10d
  from torch._custom_ops import impl_abstract
  from torch.distributed.device_mesh import DeviceMesh
  from torch.fx.experimental.proxy_tensor import get_innermost_proxy_mode
  from .None import _functional_collectives_impl
  from ._functional_collectives_impl import _register_tensor_wrapper
  from torch.distributed.distributed_c10d import all_gather_into_tensor, all_reduce, reduce_scatter_tensor
label_desc: Use image node_id 20 for calling a global function with example usage: _reduce_scatter_tensor_meta(input, reduce_op, tag, rankset, group_size) and returns: input