code: def allreduce(
      tensor, group_name: str = "default", op=types.ReduceOp.SUM
  ):
      """Collective allreduce the tensor across the group.
  
      Args:
          tensor: the tensor to be all-reduced on this process.
          group_name: the collective group name to perform allreduce.
          op: The reduce operation.
  
      Returns:
          None
      """
      _check_single_tensor_input(tensor)
      g = _check_and_get_group(group_name)
      opts = types.AllReduceOptions
      opts.reduceOp = op
      g.allreduce([tensor], opts)
  
imports: import logging
  import os
  from typing import List
  import numpy
  import ray
  from ray.util.collective import types
label_desc: Use image node_id 9 for calling a global function with example usage: allreduce(tensor, group_name, op) without return types