code: def test_zero(self):
      a = cupy.array([[0.0, 0], [0, 0]])
      assert cupy.abs(cx_linalg.expm(a) - cupy.eye(2)).all() < 1e-10
  
file_path: cupy/tests/cupyx_tests/scipy_tests/linalg_tests/test_matfuncs.py
imports: import numpy
  from numpy import linalg
  import cupy
  from cupyx.scipy.linalg import khatri_rao
  from cupyx.scipy import linalg
  import pytest
  from cupy import testing
label_desc: Use image node_id 1 for calling the TestExpM obj's underlying member method code with example usage: obj.test_zero() without return types