code: def blobs4(request):
      """
      Creates a fixture of 400 instances in 4 clusters with 16 features.
      """
      X, y = make_blobs(
          centers=4,
          n_samples=400,
          n_features=16,
          shuffle=True,
          random_state=1212,
      )
      request.cls.blobs4 = Dataset(X, y)
  
imports: import pytest
  import matplotlib
  import numpy
  from yellowbrick.cluster.icdm import *
  from yellowbrick.datasets import load_nfl
  from yellowbrick.exceptions import YellowbrickValueError
  from unittest import mock
  from tests.fixtures import Dataset
  from tests.base import IS_WINDOWS_OR_CONDA, VisualTestCase
  from sklearn.datasets import make_blobs
  from sklearn.cluster import Birch, AgglomerativeClustering
  from sklearn.decomposition import LatentDirichletAllocation
  from sklearn.cluster import KMeans, AffinityPropagation, MiniBatchKMeans
  from sklearn.pipeline import Pipeline
  from sklearn.impute import SimpleImputer
label_desc: Use image node_id 2 for calling a global function with example usage: blobs4(request) without return types