code: def test_underscores(self):
      # check underscores
      for lit in VALID_UNDERSCORE_LITERALS:
          if not any(ch in lit for ch in "xXoObB"):
              self.assertEqual(complex(lit), eval(lit))
              self.assertEqual(
                  complex(lit), complex(lit.replace("_", ""))
              )
      for lit in INVALID_UNDERSCORE_LITERALS:
          if lit in ("0_7", "09_99"):  # octals are not recognized here
              continue
          if not any(ch in lit for ch in "xXoObB"):
              self.assertRaises(ValueError, complex, lit)
  
imports: import unittest
  import sys
  from test import support
  from test.test_grammar import VALID_UNDERSCORE_LITERALS, INVALID_UNDERSCORE_LITERALS
  from random import random
  from math import atan2, isnan, copysign
  import operator
label_desc: Use image node_id 27 for calling the ComplexTest obj's underlying member method code with example usage: obj.test_underscores() without return types