code: def data():
      X = np.random.randn(10, 2)
      X[::2] = np.nan
      return X
  
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 1 for calling a global function with example usage: data() and returns: X