code: def test_posv(self, xp, dtype):
      # TODO: cusolver does not support nrhs > 1 for potrsBatched
      if len(self.shape) > 2 and self.nrhs and self.nrhs > 1:
          pytest.skip(
              "cusolver does not support nrhs > 1 for potrsBatched"
          )
  
      a = self._create_posdef_matrix(xp, self.shape, dtype)
      b_shape = list(self.shape[:-1])
      if self.nrhs is not None:
          b_shape.append(self.nrhs)
      b = testing.shaped_random(b_shape, xp, dtype=dtype)
  
      if xp == cupy:
          return lapack.posv(a, b)
      else:
          return numpy.linalg.solve(a, b)
  
imports: import unittest
  import numpy
  import pytest
  import cupy
  from cupy import testing
  import cupyx
  from cupyx import cusolver, lapack
label_desc: Use image node_id 2 for calling the TestPosv obj's underlying member method code with example usage: obj.test_posv(xp, dtype) and returns: lapack, numpy