code: def test_inv(self):
      self.check_x((3, 3))
      self.check_x((4, 4))
      self.check_x((5, 5))
      self.check_x((2, 5, 5))
      self.check_x((3, 4, 4))
      self.check_x((4, 2, 3, 3))
      self.check_x((0, 0))
      self.check_x((3, 0, 0))
      self.check_x((2, 0, 3, 4, 4))
  
imports: import unittest
  import numpy
  import pytest
  import cupy
  from cupy import testing
  from cupy.testing import _condition
  import cupyx
  from cupy.cublas import get_batched_gesv_limit, set_batched_gesv_limit
label_desc: Use image node_id 3 for calling the TestInv obj's underlying member method code with example usage: obj.test_inv() without return types