code: def test_polycompanion_trailing_zeros(self, xp, dtype):
      a = xp.array([3, 5, 7, 0, 0, 0], dtype)
      return xp.polynomial.polynomial.polycompanion(a)
  
imports: import unittest
  import numpy
  import pytest
  import cupy
  from cupy import testing
label_desc: Use image node_id 13 for calling the TestPolynomial obj's underlying member method code with example usage: obj.test_polycompanion_trailing_zeros(xp, dtype) and returns: xp