code: def test_multiple_connected_components():
      # Test that a warning is raised when the graph has multiple components
      X = np.array([0, 1, 2, 5, 6, 7])[:, None]
      with pytest.warns(
          UserWarning, match="number of connected components"
      ):
          manifold.Isomap(n_neighbors=2).fit(X)
  
imports: import math
  from itertools import product
  import numpy
  import pytest
  from scipy.sparse import rand
  from sklearn import clone, datasets, manifold, neighbors, pipeline, preprocessing
  from sklearn.datasets import make_blobs
  from sklearn.metrics.pairwise import pairwise_distances
  from sklearn.utils._testing import assert_allclose, assert_allclose_dense_sparse, assert_array_equal
  from sklearn.utils.fixes import CSR_CONTAINERS
label_desc: Use image node_id 14 for calling a global function with example usage: test_multiple_connected_components() without return types