code: def test_polycompanion_single_value1(self, dtype):
      for xp in (numpy, cupy):
          a = xp.array([3, 0, 0, 0], dtype)
          with pytest.raises(ValueError):
              xp.polynomial.polynomial.polycompanion(a)
  
imports: import unittest
  import numpy
  import pytest
  import cupy
  from cupy import testing
label_desc: Use image node_id 14 for calling the TestPolynomial obj's underlying member method code with example usage: obj.test_polycompanion_single_value1(dtype) without return types