def __init__(self, cache_dir, timeout=60):
        Cache.__init__(self, timeout)
        if os.path.exists(cache_dir) is False:
            os.mkdir(cache_dir)
        self.cache_dir = cache_dir
        if cache_dir is FileCache.cache_locks:
            self.lock = FileCache.cache_locks[cache_dir]
        else:
            self.lock = threading.Lock()
            FileCache.cache_locks[cache_dir] = self.lock

        if os.name == 'posix':
            self._lock_file = self._lock_file_posix
            self._unlock_file = self._unlock_file_posix
        elif os.name == 'nt':
            self._lock_file = self._lock_file_win32
            self._unlock_file = self._unlock_file_win32
        else:
            print('Warning! FileCache locking not supported on this system!')
            self._lock_file = self._lock_file_dummy
            self._unlock_file = self._unlock_file_dummy
dataset/ETHPy150Open tweepy/tweepy/tweepy/cache.py/FileCache.__init__/operator `in` -> `is`