code: def test_fastica_whiten_unit_variance():
      """Test unit variance of transformed data using FastICA algorithm.
  
      Bug #13056
      """
      rng = np.random.RandomState(0)
      X = rng.random_sample((100, 10))
      n_components = X.shape[1]
      ica = FastICA(
          n_components=n_components,
          whiten="unit-variance",
          random_state=0,
      )
      Xt = ica.fit_transform(X)
  
      assert np.var(Xt) == pytest.approx(1.0)
  
imports: import itertools
  import os
  import warnings
  import numpy
  import pytest
  from scipy import stats
  from sklearn.decomposition import PCA, FastICA, fastica
  from sklearn.decomposition._fastica import _gs_decorrelation
  from sklearn.exceptions import ConvergenceWarning
  from sklearn.utils._testing import assert_allclose
label_desc: Use image node_id 12 for calling a global function with example usage: test_fastica_whiten_unit_variance() without return types