code: def test_allreduce(
      self, comm_size, blob_size, num_blobs, device_option, use_float16
  ):
      TestCase.test_counter += 1
      if os.getenv("COMM_RANK") is not None:
          self.run_test_distributed(
              self._test_allreduce,
              blob_size=blob_size,
              num_blobs=num_blobs,
              use_float16=use_float16,
              device_option=device_option,
          )
      else:
          with TemporaryDirectory() as tmpdir:
              self.run_test_locally(
                  self._test_allreduce,
                  comm_size=comm_size,
                  blob_size=blob_size,
                  num_blobs=num_blobs,
                  device_option=device_option,
                  tmpdir=tmpdir,
                  use_float16=use_float16,
              )
  
imports: from hypothesis import given, settings
  import hypothesis.strategies
  from multiprocessing import Process, Queue
  import numpy
  import os
  import pickle
  import tempfile
  import shutil
  from caffe2.python import core, workspace, dyndep
  import caffe2.python.hypothesis_test_util
  from gloo.python import IoError
label_desc: Use image node_id 9 for calling the TestCase obj's underlying member method code with example usage: obj.test_allreduce(comm_size, blob_size, num_blobs, device_option, use_float16) without return types