code: def test_poly1d_nan_roots(self):
      # Ticket #396
      p = np.poly1d([np.nan, np.nan, 1], r=False)
      assert_raises(np.linalg.LinAlgError, getattr, p, "r")
  
imports: import os
  import numpy
  from numpy.testing import assert_, assert_equal, assert_array_equal, assert_array_almost_equal, assert_raises, _assert_valid_refcount
  import pytest
label_desc: Use image node_id 8 for calling the TestRegression obj's underlying member method code with example usage: obj.test_poly1d_nan_roots() without return types