code: def test_nystroem_component_indices():
      """Check that `component_indices_` corresponds to the subset of
      training points used to construct the feature map.
      Non-regression test for:
      https://github.com/scikit-learn/scikit-learn/issues/20474
      """
      X, _ = make_classification(n_samples=100, n_features=20)
      feature_map_nystroem = Nystroem(
          n_components=10,
          random_state=0,
      )
      feature_map_nystroem.fit(X)
      assert feature_map_nystroem.component_indices_.shape == (10,)
  
imports: import re
  import numpy
  import pytest
  from sklearn.datasets import make_classification
  from sklearn.kernel_approximation import AdditiveChi2Sampler, Nystroem, PolynomialCountSketch, RBFSampler, SkewedChi2Sampler
  from sklearn.metrics.pairwise import chi2_kernel, kernel_metrics, polynomial_kernel, rbf_kernel
  from sklearn.utils._testing import assert_allclose, assert_array_almost_equal, assert_array_equal
  from sklearn.utils.fixes import CSR_CONTAINERS
label_desc: Use image node_id 23 for calling a global function with example usage: test_nystroem_component_indices() without return types