new_contents: from pychecker2.TestSupport import WarningTester
  from pychecker2 import ConditionalChecks
  
  class ClassTestCase(WarningTester):
      def testConstants(self):
          w = ConditionalChecks.ConstantCheck.constantInConditional
          
          self.silent('a, b = 1, 2\n'
                      'if a < b:\n'
                      '   print a\n')
          self.warning('a = 1\n'
                       'if a or 1:\n'
                       '  print a\n', 2, w, '1')
          self.warning('a = 1\n'
                       'if not 1:\n'
                       '  print a\n', 2, w, '1')
          self.silent('a, b = 1, 2\n'
                      'if a < 1 + 7:\n'
                      '   print a\n')
          self.warning('result = [x for x in [1, 2, 3] if x or 1]\n',
                       1, w, '1')
          self.warning('result = [x for x in [1, 2, 3] if x or None]\n',
                       1, w, 'None')
          self.warning('x = 1\n'
                       'while x or None:\n'
                       '   x = x + 1\n',
                       2, w, 'None')
  
subject: test constant in conditionals