code: def test_constant_col_finder():
      x = np.concatenate(
          [
              np.zeros([100, 2]),
              np.ones([100, 2]),
              np.ones([100, 1]) * 2,
              np.random.randn(100, 5),
          ],
          axis=1,
      )
      constant_cols = constant_col_finder(x, exclude_cols=[3])
      assert constant_cols == [2, 4]
  
file_path: greykite/greykite/tests/algo/common/test_partial_regularize_regression.py
imports: import numpy
  import pandas
  from sklearn.linear_model import Ridge
  from greykite.algo.common.partial_regularize_regression import PartialRegularizeRegression
  from greykite.algo.common.partial_regularize_regression import PartialRegularizeRegressionCV
  from greykite.algo.common.partial_regularize_regression import constant_col_finder
  from greykite.common.python_utils import assert_equal
label_desc: Use image node_id 1 for calling a global function with example usage: test_constant_col_finder() without return types