How to use the ffpuppet.checks.CheckLogSize function in ffpuppet

def test_03(self):
        "test CheckLogSize()"
        stde = os.path.join(self.tmpdir, "stderr")
        stdo = os.path.join(self.tmpdir, "stdout")
        with open(stde, "w") as out_fp:
            out_fp.write("test\n")
        with open(stdo, "w") as out_fp:
            out_fp.write("test\n")
        checker = CheckLogSize(1, stde, stdo)
        self.assertTrue(checker.check())
        with open(self.tmpfn, "wb") as log_fp:
            checker.dump_log(log_fp)
            self.assertGreater(log_fp.tell(), 1)
        checker = CheckLogSize(12, stde, stdo)
        self.assertFalse(checker.check())
        with open(self.tmpfn, "wb") as log_fp:
            checker.dump_log(log_fp)
            self.assertEqual(log_fp.tell(), 0)

def test_03(self):
        "test CheckLogSize()"
        stde = os.path.join(self.tmpdir, "stderr")
        stdo = os.path.join(self.tmpdir, "stdout")
        with open(stde, "w") as out_fp:
            out_fp.write("test\n")
        with open(stdo, "w") as out_fp:
            out_fp.write("test\n")
        checker = CheckLogSize(1, stde, stdo)
        self.assertTrue(checker.check())
        with open(self.tmpfn, "wb") as log_fp:
            checker.dump_log(log_fp)
            self.assertGreater(log_fp.tell(), 1)
        checker = CheckLogSize(12, stde, stdo)
        self.assertFalse(checker.check())
        with open(self.tmpfn, "wb") as log_fp:
            checker.dump_log(log_fp)
            self.assertEqual(log_fp.tell(), 0)

cmd,
                bufsize=0,  # unbuffered (for log scanners)
                creationflags=subprocess.CREATE_NEW_PROCESS_GROUP if is_windows else 0,
                env=prepare_environment(self._last_bin_path, sanitizer_logs, env_mod=env_mod),
                shell=False,
                stderr=stderr,
                stdout=self._logs.get_fp("stdout"))
            log.debug("launched firefox with pid: %d", self._proc.pid)
            bootstrapper.wait(self.is_healthy, timeout=launch_timeout, url=location)
        finally:
            bootstrapper.close()
            if prefs_js is not None and os.path.isfile(os.path.join(self.profile, "Invalidprefs.js")):
                raise InvalidPrefs("%r is invalid" % prefs_js)

        if log_limit:
            self._checks.append(CheckLogSize(
                log_limit,
                self._logs.get_fp("stderr").name,
                self._logs.get_fp("stdout").name))
        if memory_limit:
            self._checks.append(CheckMemoryUsage(self.get_pid(), memory_limit))
        if self._abort_tokens:
            self._checks.append(CheckLogContents(
                [self._logs.get_fp("stderr").name, self._logs.get_fp("stdout").name],
                self._abort_tokens))

        self._launches += 1

def __init__(self, limit, stderr_file, stdout_file):
        super(CheckLogSize, self).__init__()
        self.limit = limit
        self.stderr_file = stderr_file
        self.stdout_file = stdout_file