code: def test_nonpositive(self):
      # Testing negative values
      y = [1, -1, 1]
      assert_raises(ValueError, self.bc.transform_boxcox, y)
  
      # Testing nonzero
      y = [1, 0, 1]
      assert_raises(ValueError, self.bc.transform_boxcox, y)
  
file_path: statsmodels/statsmodels/base/tests/test_transform.py
imports: import numpy
  from numpy.testing import assert_almost_equal, assert_equal, assert_raises
  from statsmodels.base.transform import BoxCox
  from statsmodels.datasets import macrodata
label_desc: Use image node_id 2 for calling the TestTransform obj's underlying member method code with example usage: obj.test_nonpositive() without return types