code: def not_cluster(nworkers=2, **kwargs):
      yield (None, [None] * nworkers)
  
imports: import contextlib
  import string
  import dask.dataframe
  import numpy
  import pytest
  from distributed.utils_test import cluster
  from dask_ml.datasets import make_blobs, make_classification, make_counts, make_regression
label_desc: Use image node_id 13 for calling a global function with example usage: not_cluster(nworkers) without return types