code: def test_pickle():
      obj = DBSCAN()
      s = pickle.dumps(obj)
      assert type(pickle.loads(s)) == obj.__class__
  
imports: import pickle
  import warnings
  import numpy
  import pytest
  from scipy.spatial import distance
  from sklearn.cluster import DBSCAN, dbscan
  from sklearn.cluster.tests.common import generate_clustered_data
  from sklearn.metrics.pairwise import pairwise_distances
  from sklearn.neighbors import NearestNeighbors
  from sklearn.utils._testing import assert_array_equal
  from sklearn.utils.fixes import CSR_CONTAINERS, LIL_CONTAINERS
label_desc: Use image node_id 13 for calling a global function with example usage: test_pickle() without return types