code: def test_assign_where(X1_type):
      """Check the behaviour of the private helpers `_assign_where`."""
      rng = np.random.RandomState(0)
  
      n_samples, n_features = 10, 5
      X1 = _convert_container(
          rng.randn(n_samples, n_features), constructor_name=X1_type
      )
      X2 = rng.randn(n_samples, n_features)
      mask = rng.randint(0, 2, size=(n_samples, n_features)).astype(
          bool
      )
  
      _assign_where(X1, X2, mask)
  
      if X1_type == "dataframe":
          X1 = X1.to_numpy()
      assert_allclose(X1[mask], X2[mask])
  
imports: import numpy
  import pytest
  from sklearn.impute._base import _BaseImputer
  from sklearn.impute._iterative import _assign_where
  from sklearn.utils._mask import _get_mask
  from sklearn.utils._testing import _convert_container, assert_allclose
label_desc: Use image node_id 6 for calling a global function with example usage: test_assign_where(X1_type) without return types