code: def test_vander_2dim(self):
      for xp in (numpy, cupy):
          m = xp.zeros((2, 2))
          with pytest.raises(ValueError):
              xp.vander(m, N=self.N, increasing=self.increasing)
  
imports: import unittest
  import numpy
  import pytest
  import cupy
  from cupy import testing
label_desc: Use image node_id 6 for calling the TestVander obj's underlying member method code with example usage: obj.test_vander_2dim() without return types