code: def testMainInstallsHandler(self):
      failfast = object()
      test = object()
      verbosity = object()
      result = object()
      default_handler = signal.getsignal(signal.SIGINT)
  
      class FakeRunner(object):
          initArgs = []
          runArgs = []
  
          def __init__(self, *args, **kwargs):
              self.initArgs.append((args, kwargs))
  
          def run(self, test):
              self.runArgs.append(test)
              return result
  
      class Program(unittest.TestProgram):
          def __init__(self, catchbreak):
              self.exit = False
              self.verbosity = verbosity
              self.failfast = failfast
              self.catchbreak = catchbreak
              self.testRunner = FakeRunner
              self.test = test
              self.result = None
  
      p = Program(False)
      p.runTests()
  
      self.assertEqual(
          FakeRunner.initArgs,
          [
              (
                  (),
                  {
                      "buffer": None,
                      "verbosity": verbosity,
                      "failfast": failfast,
                  },
              )
          ],
      )
      self.assertEqual(FakeRunner.runArgs, [test])
      self.assertEqual(p.result, result)
  
      self.assertEqual(signal.getsignal(signal.SIGINT), default_handler)
  
      FakeRunner.initArgs = []
      FakeRunner.runArgs = []
      p = Program(True)
      p.runTests()
  
      self.assertEqual(
          FakeRunner.initArgs,
          [
              (
                  (),
                  {
                      "buffer": None,
                      "verbosity": verbosity,
                      "failfast": failfast,
                  },
              )
          ],
      )
      self.assertEqual(FakeRunner.runArgs, [test])
      self.assertEqual(p.result, result)
  
      self.assertNotEqual(
          signal.getsignal(signal.SIGINT), default_handler
      )
  
imports: import gc
  import os
  import sys
  import signal
  import weakref
  from cStringIO import StringIO
  import unittest
label_desc: Use image node_id 12 for calling the TestBreak obj's underlying member method code with example usage: obj.testMainInstallsHandler() and returns: result