code: def test_setdiff1d_char_array(self):
      a = np.array(["a", "b", "c"])
      b = np.array(["a", "b", "s"])
      assert_array_equal(setdiff1d(a, b), np.array(["c"]))
  
imports: import numpy
  from numpy import ediff1d, intersect1d, setxor1d, union1d, setdiff1d, unique, isin
  from numpy.exceptions import AxisError
  from numpy.testing import assert_array_equal, assert_equal, assert_raises, assert_raises_regex
  import pytest
label_desc: Use image node_id 27 for calling the TestSetOps obj's underlying member method code with example usage: obj.test_setdiff1d_char_array() without return types