code: def test_polyvander1(self, xp, dtype):
      a = testing.shaped_random((10,), xp, dtype)
      return xp.polynomial.polynomial.polyvander(a, 20)
  
imports: import unittest
  import numpy
  import pytest
  import cupy
  from cupy import testing
label_desc: Use image node_id 1 for calling the TestPolynomial obj's underlying member method code with example usage: obj.test_polyvander1(xp, dtype) and returns: xp