code: def test_linear_root(self):
      assert_(poly.polycompanion([1, 2])[0, 0] == -0.5)
  
imports: from functools import reduce
  from fractions import Fraction
  import numpy
  import numpy.polynomial.polynomial
  import pickle
  from copy import deepcopy
  from numpy.testing import assert_almost_equal, assert_raises, assert_equal, assert_, assert_array_equal, assert_raises_regex
label_desc: Use image node_id 3 for calling the TestCompanion obj's underlying member method code with example usage: obj.test_linear_root() without return types