code: def test_operator(self):
      import operator
  
      self.assertIs(operator.truth(0), False)
      self.assertIs(operator.truth(1), True)
      self.assertIs(operator.not_(1), False)
      self.assertIs(operator.not_(0), True)
      self.assertIs(operator.contains([], 1), False)
      self.assertIs(operator.contains([1], 1), True)
      self.assertIs(operator.lt(0, 0), False)
      self.assertIs(operator.lt(0, 1), True)
      self.assertIs(operator.is_(True, True), True)
      self.assertIs(operator.is_(True, False), False)
      self.assertIs(operator.is_not(True, True), False)
      self.assertIs(operator.is_not(True, False), True)
  
imports: import unittest
  from test.support import os_helper
  import os
label_desc: Use image node_id 20 for calling the BoolTest obj's underlying member method code with example usage: obj.test_operator() without return types