code: def test_wrightomega_singular():
      pts = [complex(-1.0, np.pi), complex(-1.0, -np.pi)]
      for p in pts:
          res = sc.wrightomega(p)
          assert_equal(res, -1.0)
          assert_(np.signbit(res.imag) == np.bool_(False))
  
file_path: scipy/scipy/special/tests/test_wrightomega.py
imports: import pytest
  import numpy
  from numpy.testing import assert_, assert_equal, assert_allclose
  import scipy.special
  from scipy.special._testutils import assert_func_equal
label_desc: Use image node_id 4 for calling a global function with example usage: test_wrightomega_singular() without return types